JP6425564B2 - Anchor coating agent for polypropylene resin extrusion lamination, packaging material and method for producing the same - Google Patents

Description

  The present invention relates to an anchor coating agent for extrusion laminating a polypropylene resin to a substrate, and a packaging material obtained using the same.

  Packaging materials generally have a laminate structure in which a plurality of layers are laminated. For example, a packaging material is used in which a thermoplastic resin film such as a polyester resin film or a polyamide resin film is used as a base material, and a sealant layer containing a polypropylene resin is laminated thereon via an adhesive layer. The polypropylene resin is excellent in heat resistance and oil resistance, and is particularly preferably used for a sealant layer of a packaging material applied to products using edible oil such as snack foods, bread and noodles.

In order to produce such a laminate, for example, after providing an adhesive layer by coating and drying on a substrate such as a thermoplastic resin film, the sealant resin film formed into a film in advance is pressed by a heating roll. After the adhesive layer is provided on the adhesive layer by applying a dry lamination method (also referred to as dry lamination) or on a substrate by coating and drying, the sealant resin is extruded from the extruder on the adhesive layer, Methods such as extrusion lamination (also referred to as extrusion lamination) for forming a sealant layer are employed.
The extrusion laminating method can form a sealant layer by melt-extruding the sealant resin directly on the substrate provided with the adhesive layer, and therefore, there is an advantage that the sealant resin does not need to be formed into a film in advance, and the adhesive layer Is advantageous in that sufficient adhesion can be obtained even in the case of a thin film, it becomes possible to mass-produce the laminate at low cost, and is preferably employed among those skilled in the art. However, when a polypropylene resin is used as the sealant resin, the polypropylene resin has a problem in adhesiveness, and therefore, it is necessary to further study to obtain a laminate by an extrusion laminating method using the polypropylene resin.

  On the other hand, the packaging material is filled with various contents such as food. However, if volatile matter such as oil or medicinal ingredient is contained in the contents, these will penetrate between the substrate and the sealant layer, causing swelling or dissolution of the adhesive layer, There has been a problem that the adhesive strength between the base material layer and the sealant layer is lowered with time or peeled off (delamination). Therefore, the packaging material has the ability to suppress the phenomenon in which the adhesive strength between the base material layer and the sealant layer decreases with time or peels off even when such content is contained (content resistance Is required to have

  Thus, a packaging material that can be manufactured by extrusion lamination of a polypropylene resin and is excellent in content resistance is required. In particular, in the packaging material for snack food which consumes a large amount among packaging materials, a sealant layer made of polypropylene resin is laminated on the thermoplastic resin film surface of a thermoplastic resin film having a metal deposition layer on one side through an adhesive layer. In snack food packaging materials, there is a need for a technique for extrusion laminating a polypropylene resin on a thermoplastic resin film substrate.

  Patent Document 1 and Patent Document 2 disclose a packaging material obtained by providing an adhesive layer (anchor coat layer) on the surface of a metal-based barrier layer such as aluminum foil and extruding and laminating a polypropylene resin thereon. No mention is made of a technique for extruding and laminating a polypropylene resin on a thermoplastic resin film substrate such as a polyester resin film or a polyamide resin film.

In the field of adhesion technology, the combination of the type of substrate to be an adherend and the type of adhesive greatly affects the adhesion performance. Usually, an adhesive (anchor coating agent) comprising an acid-modified polyolefin resin as used in Patent Document 1 and Patent Document 2 is excellent in adhesion to a metal substrate, but a polyester resin film, a polyamide resin film, etc. The adhesiveness to the thermoplastic resin film of the above tends to be poor.
Thus, in the extrusion laminating technique of polypropylene resin, it has become more difficult to extrusion laminate polypropylene resin to a thermoplastic resin film substrate.

  On the other hand, Patent Document 3 proposes a packaging material in which a polypropylene resin is extruded and laminated on a thermoplastic resin film substrate. However, in the packaging material of Patent Document 3, it is necessary to provide a plurality of adhesive layers on a thermoplastic resin film substrate, and the manufacturing process is complicated and expensive. Furthermore, if the line speed during extrusion lamination is a high speed of 100 m / min or more, the laminate may become insufficient as the speed increases, and in particular, the consumption amount is large, and the speeding up of the production line is required. There have been productivity issues in applying this technology to the manufacture of snack packaging materials. In addition, the resulting packaging material was also insufficient in contents resistance.

  By the way, although the packaging material obtained by extrusion laminating of a polypropylene resin is a level which does not pose a problem in particular normally, the slight smell (PP odor) originating in a polypropylene resin may be confirmed. Among snack foods, potato snacks such as potato chips, which are popular among consumers and consume a large amount of consumption, have a slight but distinctive odor (sunlight odor), and this dainty odor and the PP odor of the packaging material If you smell it at the same time, it may be felt as a peculiar unpleasant smell, which has been a cause of deteriorating the flavor of potato snacks. Therefore, in the packaging material for potato snacks, suppression of PP odor has been a problem.

  As described above, in the production of a packaging material for potato snacks and snacks, suppression of the PP odor of the packaging material has been required in order to adopt the extrusion laminating method of polypropylene resin. In addition, in the production of packaging materials used for snacks, not only for potato snacks, speeding up of the line speed has been required.

JP, 2001-102011, A Japanese Patent Application Publication No. 2008-230198 JP, 2012-201043, A

  The present invention overcomes the above-mentioned drawbacks of the prior art, and is an anchor coating agent for extrusion-laminating a polypropylene resin on a substrate such as a thermoplastic resin film to produce a packaging material Even when the line speed is increased, the adhesion between the base material and the extruded polypropylene resin layer is excellent, and the obtained packaging material is excellent in contents resistance and has a PP odor suppressed. It is an object of the present invention to provide an anchor coating agent capable of

  As a result of intensive studies to solve the above problems, the present inventors have found that an aqueous dispersion containing an acid-modified polypropylene resin of a specific structure is suitable as an anchor coating agent for polypropylene resin extrusion lamination. It has been found that a packaging material obtained by extrusion lamination of a polypropylene resin using an anchor coating agent is excellent in productivity and can reduce the odor derived from the polypropylene resin, resulting in the present invention.

That is, the gist of the present invention is as follows.
(1) an aqueous dispersion containing an acid-modified polypropylene resin and the aqueous medium, the polypropylene component of the acid-modified polypropylene resin, Ri homopolypropylene der consisting isotactic structure, a side chain with respect to the polypropylene backbone in a mismatch which is a ratio of the direction of the mismatch of the methyl group, an anchor polypropylene resin extrusion lamination, wherein 3.0 mol% or less der Rukoto methyl group in 100 mol% is the side chain of the polypropylene resin Coating agent.
(2) The anchor coating agent for polypropylene resin extrusion lamination according to (1), wherein the acid-modified polypropylene resin is an isotactic polypropylene- (anhydride) maleic acid binary copolymer.
(3) The anchor coating agent for polypropylene resin extrusion lamination according to (1) or (2), wherein the remaining amount of unreacted unsaturated carboxylic acid component contained in the acid-modified polypropylene resin is 50 to 10,000 ppm. .
(4) 1 to 100 parts by mass of at least one resin selected from polyethylene resin, polyurethane resin, and polyester resin with respect to 100 parts by mass of acid-modified polypropylene resin is characterized by (1) to (3) The anchor coat agent for polypropylene resin extrusion lamination as described in any of the above.
(5) A packaging material comprising at least a thermoplastic resin film layer, an anchor coat layer, and an extruded polypropylene resin layer laminated in this order, wherein the anchor coat layer is any one of (1) to (4) A packaging material characterized in that it is a coating film formed of an anchor coating agent for polypropylene resin extrusion lamination.
(6) The packaging material according to (5), which is a packaging material for snack food.
(7) The packaging material according to (6), wherein the packaging material for snack food is a packaging material for potato snack food.
(8) The anchor coat agent for polypropylene resin extrusion lamination according to any one of the above (1) to (4) was applied to at least one surface of a thermoplastic resin film layer and dried to form an anchor coat layer Thereafter, a molten polypropylene resin is laminated by extrusion lamination on the formed anchor coat layer.
(9) The method for producing a packaging material according to (8), wherein the line speed at the time of laminating the polypropylene resin by extrusion lamination is 100 to 600 m / min.

  The anchor coat agent of the present invention can be applied to a base material to form an anchor coat layer, whereby a polypropylene resin can be extruded and laminated, and a packaging material obtained therefrom is excellent in content resistance. Moreover, it is possible to employ | adopt a thermoplastic resin film as a base material, and it is possible to use for manufacture of snack food packaging material. Furthermore, the line speed at the time of extruding and laminating polypropylene resin can be operated at a high speed of 100 m / min or more, and the productivity is excellent. In addition, the PP odor of the packaging material is suppressed, and the potato snacks such as potato chips can be packaged without losing their flavor. In addition, since it is a water-based anchor coating agent, it also has the effect of preserving the manufacturing environment and the global environment.

Hereinafter, the present invention will be described in detail.
The anchor coating agent for polypropylene resin extrusion lamination of the present invention is an aqueous dispersion containing an acid-modified polypropylene resin and an aqueous medium.

  In the present invention, the acid-modified polypropylene resin needs to be a homopolypropylene in which the polypropylene component has an isotactic structure. When the polypropylene has a structure such as a syndiotactic structure or an atactic structure other than the isotactic structure, the adhesion between the thermoplastic resin film substrate and the extruded polypropylene resin tends to be poor. Here, an isotactic structure means the structure where the methyl group which is a side chain is located in the same direction with respect to a polypropylene principal chain. However, even in the case of an isotactic polypropylene resin in general, slight mismatch may be observed in the direction of the methyl group which is a side chain with respect to the polypropylene main chain. In the present invention, the methyl group 100 is a side chain of a polypropylene resin, in which the proportion of mismatch in the direction of the methyl group which is a side chain with respect to such a polypropylene main chain (hereinafter sometimes referred to as “mismatch rate”). It is preferably 3.0 mol% or less, more preferably 2.0 mol% or less, still more preferably 1.0 mol% or less, and still more preferably 0.5 mol% or less. Is particularly preferred. If the mismatch rate exceeds 3 mol%, the adhesion to the thermoplastic resin film substrate tends to be reduced.

  The polypropylene resin is generally a terpolymer which is a homopolypropylene consisting only of a propylene component, a random polypropylene or block polypropylene containing 4 to 5% by mass of an ethylene component, or a polypropylene terpolymer containing an ethylene component or a 1-butene component. It can be classified into polymers etc. However, the polypropylene component of the acid-modified polypropylene resin in the present invention is required to be homopolypropylene in which the olefin component is composed only of the propylene component. When the polypropylene component of the acid-modified polypropylene resin is a polypropylene other than homopolypropylene, such as random polypropylene, block polypropylene, terpolymer, etc., the adhesiveness between the thermoplastic resin film substrate and the extruded polypropylene resin tends to be inferior. .

The acid-modified polypropylene resin in the present invention is obtained by acid-modifying homopolypropylene having the above-described isotactic structure with an unsaturated carboxylic acid component.
Examples of unsaturated carboxylic acid components used for acid modification include acrylic acid, methacrylic acid, (anhydride) maleic acid, (anhydride) itaconic acid, fumaric acid, crotonic acid, etc., and half esters of unsaturated dicarboxylic acids, half amides Etc. Among them, acrylic acid, methacrylic acid and (anhydride) maleic acid are preferable from the viewpoint of adhesiveness, and in particular (maleic anhydride) is preferable. In addition, "(anhydride)-acid" means "-acid or anhydride-acid." That is, (anhydride) maleic acid means maleic acid or maleic anhydride.
The unsaturated carboxylic acid component may be copolymerized in the acid-modified polypropylene resin, and the form thereof is not limited. As the state of copolymerization, for example, random copolymerization, block copolymerization, graft copolymerization (grafting Denatured) and the like, and graft copolymerization is preferred from the viewpoint of ease of production and adhesiveness.

The graft copolymerization method for introducing the unsaturated carboxylic acid component into the polypropylene resin is not particularly limited. For example, the polypropylene resin and the unsaturated carboxylic acid are heated and melted to a temperature above the melting point of the polypropylene resin in the presence of a radical generator. A method of reacting or a method of dissolving a polypropylene resin and an unsaturated carboxylic acid in an organic solvent and then heating and stirring in the presence of a radical generating agent may be mentioned. The former method is preferred because the operation is simple.
Examples of a radical generator used for graft copolymerization include di-tert-butyl peroxide, dicumyl peroxide, tert-butyl hydroperoxide, tert-butyl cumyl peroxide, benzoyl peroxide, dilauryl peroxide, Organic peroxides such as cumene hydroperoxide, tert-butylperoxybenzoate, ethyl ethyl ketone peroxide, di-tert-butyldiperphthalate, and azonitriles such as azobisisobutyronitrile can be mentioned. These may be appropriately selected and used depending on the reaction temperature.

  0.1-10 mass% is preferable, as for content of the unsaturated carboxylic acid component as a copolymerization component in acid-modified polypropylene resin, 1-7 mass% is more preferable, and 2-5 mass% is more preferable. If the content of the unsaturated carboxylic acid component is less than 0.1% by mass, processing into an aqueous dispersion to be described later tends to be difficult, and sufficient adhesiveness tends to be difficult to obtain. On the other hand, if it exceeds 10% by mass, the adhesion to the extruded polypropylene resin layer tends to be lowered.

  In the present invention, the acid-modified polypropylene resin may contain a component other than the olefin component and the unsaturated carboxylic acid component, for example, a component such as (meth) acrylic acid ester as a copolymerization component. The content of such a copolymerization component is not particularly limited as long as the effects of the present invention are not impaired, but it is preferably 20% by mass or less of the acid-modified polypropylene resin.

  The most preferable specific example of the acid-modified polypropylene resin in the present invention is an isotactic polypropylene- (anhydride) maleic acid binary copolymer. What the adhesiveness with thermoplastic resin film base materials, such as a polyester resin film and a polyamide resin film, is more excellent because acid-modified polypropylene resin is an isotactic polypropylene-(anhydride) maleic acid binary copolymer In addition, the line speed can be increased and the PP odor can be effectively suppressed. The (anhydride) maleic acid in the isotactic polypropylene- (anhydride) maleic acid binary copolymer may be either maleic anhydride or maleic acid, or both may be mixed. The composition in which both are mixed means isotactic polypropylene-maleic anhydride-maleic acid copolymer, and in the present invention, this copolymer also has isotactic polypropylene- (anhydride) maleic acid binary copolymer. Included in the union.

  The melt flow rate at 2160 g load at 170 ° C., which is an index of the molecular weight of the acid-modified polypropylene resin, is preferably 0.01 to 300 g / 10 min, and more preferably 0.1 to 100 g / 10 min. More preferably, it is 1 to 50 g / 10 min, and particularly preferably 1 to 20 g / 10 min. If the melt flow rate exceeds 300 g / 10 min, the content resistance tends to be lowered, and if it is less than 0.01 g / 10 min, the manufacturing aspect in increasing the molecular weight of the resin may be restricted. is there.

  The acid-modified polypropylene resin preferably has a melting point of 100 to 200 ° C., more preferably 120 to 180 ° C., and still more preferably 130 to 170 ° C., from the viewpoint of heat resistance. Is particularly preferred.

  In the acid-modified polypropylene resin of the present invention, the remaining amount of the unreacted unsaturated carboxylic acid monomer component contained in the acid-modified polypropylene resin is preferably 50 to 10,000 ppm, and more preferably 100 to 7,000 ppm. Preferably, it is 200 to 5,000 ppm, more preferably 300 to 3,000 ppm, and most preferably 300 to 2,000 ppm. When the residual amount of the unreacted unsaturated carboxylic acid monomer component is in the above-mentioned preferable range, the adhesion between the thermoplastic resin film substrate and the extruded polypropylene resin and the content resistance, and further the line speed and PP odor Excellent in the suppression effect of Here, the remaining amount of the unreacted unsaturated carboxylic acid monomer component is an acid in a free state without reacting with the polypropylene resin among the unsaturated carboxylic acid monomer components used as a raw material in the production of the acid-modified polypropylene resin. The amount of unsaturated carboxylic acid monomer component remaining in the modified polypropylene resin is meant.

  The remaining amount of the unreacted unsaturated carboxylic acid monomer component contained in the acid-modified polypropylene resin is obtained, for example, by heating and depressurizing the acid-modified polypropylene resin before producing an aqueous dispersion from the acid-modified polypropylene resin and the aqueous medium. A method of distilling off unreacted unsaturated carboxylic acid monomer component, a method of separating an unreacted unsaturated carboxylic acid monomer component by dissolving acid-modified polypropylene resin in a solvent and reprecipitating, acid-denatured powder or pellets The polypropylene resin can be washed with a liquid such as water or an organic solvent and reduced by a method such as removing unreacted unsaturated carboxylic acid monomer component.

Among these methods, a method of washing powder or pelletized acid-modified polypropylene resin using water, an organic solvent or the like as a washing solution is preferable because of its high reduction effect.
As the organic solvent used for the cleaning solution, it is preferable to select one having poor solubility in acid-modified polypropylene resin and excellent in solubility in the unsaturated carboxylic acid monomer component. Specifically, methanol, ethanol, propanol, It is preferable to use an alcohol such as butanol or acetone.

Moreover, it becomes possible to reduce the residual amount of an unsaturated carboxylic acid component efficiently by using what added the organic amine as a washing | cleaning liquid. Organic amines which can be added to the washing solution include triethylamine, N, N-dimethylethanolamine, isopropylamine, aminoethanol, dimethylaminoethanol, diethylaminoethanol, ethylamine, diethylamine, isobutylamine, dipropylamine, 3-ethoxypropylamine, 3 -Diethylaminopropylamine, sec-butylamine, propylamine, n-butylamine, 2-methoxyethylamine, 3-methoxypropylamine, 2,2-dimethoxyethylamine, monoethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine, Pyrrole, pyridine and the like can be mentioned.
The content of the organic amine in the cleaning solution is preferably 0.5 to 30 parts by mass, and 1 to 10 parts by mass with respect to 100 parts by mass of the cleaning solution, from the viewpoint of the reduction efficiency of the unreacted unsaturated carboxylic acid monomer component. It is more preferable that

  As a specific washing | cleaning method, the method of mixing and heating and stirring the acid-modified polypropylene resin made into powder or pellet form, and the washing | cleaning liquid which consists of water, an organic solvent, etc. is mentioned, for example. In addition, the residual amount can be further reduced by increasing the number of times of cleaning. The amount of the washing solution is preferably equal to or more than the acid-modified polypropylene resin. As a washing | cleaning temperature, it is preferable that it is high temperature in the range which there is neither melt | dissolution nor deformation | transformation of resin. As a washing | cleaning time, 30 minutes or more are preferable, and 60 minutes or more are more preferable. It is preferable that the acid-modified polypropylene resin after washing be dried by heating, reduced pressure, or the like.

Next, the aqueous medium in the present invention will be described.
The aqueous dispersion in the present invention contains the above-mentioned acid-modified polypropylene resin and an aqueous medium. The aqueous medium is water or a liquid containing water as a main component, and may contain a basic compound or an organic solvent described later.

  The aqueous medium in the present invention preferably contains a basic compound. The carboxyl group of the acid-modified polypropylene resin contained in the aqueous dispersion is neutralized by the basic compound, and the electrical repulsion between the produced carboxyl anions prevents the aggregation between the fine particles, resulting in stable dispersion in the aqueous dispersion. Sex is given. Any basic compound may be used as long as it can neutralize a carboxyl group, but it is preferable to use a volatile compound from the viewpoint of maintaining good performance of the packaging material when used for the packaging material.

As a basic compound, ammonia and an organic amine are preferable. Specific examples of organic amines include triethylamine, N, N-dimethylethanolamine, isopropylamine, aminoethanol, dimethylaminoethanol, diethylaminoethanol, ethylamine, diethylamine, isobutylamine, dipropylamine, 3-ethoxypropylamine, 3- Diethylaminopropylamine, sec-butylamine, propylamine, n-butylamine, 2-methoxyethylamine, 3-methoxypropylamine, 2,2-dimethoxyethylamine, monoethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine, pyrrole And pyridine.
The content of the basic compound is preferably 0.5 to 10 times equivalent to the carboxyl group in the acid-modified polypropylene resin, more preferably 0.8 to 5 times equivalent, and 0.9 to It is particularly preferred that it is 3.0 times equivalent. When the content of the basic compound is less than 0.5 times equivalent, the addition effect of the basic compound is not recognized, while when the content exceeds 10 times equivalent, the drying time at the time of forming the anchor coat layer is long. And the stability of the aqueous dispersion may be reduced.

The aqueous medium in the present invention may further contain an organic solvent. The wettability to a substrate can be improved by containing an organic solvent. Furthermore, by adding an organic solvent at the time of the aqueous dispersion of the acid-modified polypropylene resin described later, the aqueous dispersion can be promoted and the dispersed particle size can be reduced.
The content of the organic solvent in the aqueous dispersion is preferably 50% by mass or less, more preferably 0.1 to 45% by mass, and more preferably 2 to 40% by mass with respect to the entire aqueous dispersion. Is more preferable, and 3 to 35% by mass is particularly preferable. When the content of the organic solvent exceeds 50% by mass, the stability of the aqueous dispersion may be reduced.
The organic solvent contained in the aqueous dispersion preferably has a solubility in water of 20 ° C. of 10 g / L or more, more preferably 20 g / L or more, from the viewpoint of aqueous dispersion promotion performance and dispersion stability. Preferably, it is 50 g / L or more.
In addition, the boiling point of the organic solvent is preferably 200 ° C. or less from the viewpoint of drying property when the anchor coat agent containing the aqueous dispersion is dried to obtain the anchor coat layer. The organic solvent whose boiling point exceeds 200 degreeC tends to remain | survive in an anchor coat layer, and adhesiveness etc. may fall.

As the organic solvent, for example, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert-amyl alcohol, Alcohols such as 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol, cyclohexanol, ketones such as methyl ethyl ketone, methyl isobutyl ketone, ethyl butyl ketone, cyclohexanone, ethers such as tetrahydrofuran, dioxane Ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, 3-methoxybutyl acetate, methyl propionate, pro Esters such as ethyl carbonate, diethyl carbonate, dimethyl carbonate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, glycol derivatives such as ethylene glycol ethyl ether acetate, and the like -Methoxy-2-propanol, 1-ethoxy-2-propanol, 3-methoxy-3-methyl-1-butanol, methoxybutanol, acetonitrile, dimethylformamide, dimethylacetamide, diacetone alcohol, ethyl acetoacetate, 1,2- Dimethyl glycerol, 1,3-dimethyl glycerol, trimethyl glycerol etc. are mentioned.
Among them, ethanol, n-propanol, isopropanol, n-butanol, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether are aqueous of acid-modified polyolefin resin It is effective and preferable to promote dispersion.
In the present invention, a plurality of these organic solvents may be mixed and used.

Next, the aqueous dispersion in the present invention will be described.
The aqueous dispersion in the present invention contains an acid-modified polypropylene resin and an aqueous medium, and the acid-modified polypropylene resin is dispersed in the aqueous medium.

  The number average particle diameter of the acid-modified polypropylene resin particles dispersed in the aqueous dispersion is preferably 0.5 μm or less from the viewpoint of adhesion when the extrusion laminating line speed is increased, and it is preferably 0. The thickness is more preferably 0.001 to 0.3 μm, still more preferably 0.01 to 0.2 μm, particularly preferably 0.02 to 0.1 μm, and preferably 0.02 to 0.07 μm. Is most preferred.

  In the present invention, the content of the acid-modified polypropylene resin in the aqueous dispersion can be appropriately selected according to the coating conditions, coating thickness, performance, etc., and is not particularly limited, but the viscosity of the aqueous dispersion is kept appropriate. And from the viewpoint of expressing good coating properties, it is preferably 1 to 60% by mass, more preferably 3 to 55% by mass, still more preferably 5 to 50% by mass, and 10 to 45% by mass. % Is particularly preferred.

  The viscosity of the aqueous dispersion in the present invention is not particularly limited, but the viscosity measured under a condition of 20 ° C. with a B-type viscometer is preferably 4 to 100,000 mPa · s. The pH of the aqueous dispersion is also not particularly limited, but is preferably 6 to 12.

  The aqueous dispersion in the present invention preferably contains substantially no nonvolatile aqueous dispersion aid. The present invention does not exclude the use of a non-volatile aqueous dispersion aid, but is stable in an aqueous medium with an acid-modified polypropylene resin having a number average particle diameter of 0.5 μm or less without using an aqueous dispersion aid Can be distributed. The aqueous dispersion in the present invention is substantially free of the non-volatile aqueous dispersion aid, and thus is excellent in adhesiveness, content resistance and water resistance, and these performances hardly change even in the long run.

  Here, the term "aqueous dispersion aid" refers to a drug or compound added for the purpose of promoting aqueous dispersion or stabilizing aqueous dispersion in the production of aqueous dispersion, and "non-volatile" Indicates that it does not have a boiling point at normal pressure, or has a high boiling point (eg, 300 ° C. or higher) at normal pressure.

  The phrase "substantially free of the non-volatile aqueous dispersion aid" means that such an aid is not used at the time of production (at the time of aqueous dispersion of the acid-modified polypropylene resin), and the resulting aqueous dispersion is It means that it does not contain an agent. Therefore, it is particularly preferable that the content of the aqueous dispersion aid is zero, but the content is 5% by mass or less, preferably 2% by mass or less based on the acid-modified polypropylene resin, as long as the effects of the present invention are not impaired. More preferably, less than 0.5% by mass may be contained.

  Examples of the non-volatile aqueous dispersion aid as referred to in the present invention include an emulsifying agent described later, a compound having a protective colloid action, modified waxes, an acid modified compound having a high acid value, a water-soluble polymer and the like.

  As an emulsifier, a cationic emulsifier, an anionic emulsifier, a nonionic emulsifier, or an amphoteric emulsifier is mentioned, In addition to what is generally used for emulsion polymerization, surfactant is also contained. For example, as an anionic emulsifier, sulfates of higher alcohols, higher alkyl sulfonates, higher carboxylates, alkyl benzene sulfonates, polyoxyethylene alkyl sulfate salts, polyoxyethylene alkyl phenyl ether sulfate salts, vinyl sulfosuccinic acid And nonionic emulsifiers such as 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 Compounds having a polyoxyethylene structure such as a copolymer, and sorbitan derivatives such as polyoxyethylene sorbitan fatty acid ester And examples of the amphoteric emulsifiers, lauryl betaine, lauryl dimethyl amine oxide, and the like.

  Compounds having protective colloid action, modified waxes, acid-modified compounds with high acid value, and water-soluble polymers such as polyvinyl alcohol, carboxyl group-modified polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, modified starch, polyvinyl pyrrolidone Acid-modified polyolefin waxes and their salts generally having a number average molecular weight of 5000 or less, such as polyacrylic acid and salts thereof, carboxyl group-containing polyethylene wax, carboxyl group-containing polypropylene wax and carboxyl group-containing polyethylene-propylene wax, acrylic acid-anhydride Maleic acid copolymer and its salt, styrene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid copolymer, isobutylene-anthracene anhydride Carboxyl group-containing polymers having an unsaturated carboxylic acid content of 10% by mass or more, such as acid alternating copolymers, (meth) acrylic acid- (meth) acrylic acid ester copolymers and the like, salts thereof, polyitaconic acid and salts thereof, amino Water-soluble acrylic copolymers having a group, gelatin, gum arabic, casein and the like, compounds generally used as a dispersion stabilizer for fine particles, and the like can be mentioned.

Next, the method for producing the aqueous dispersion in the present invention will be described.
As a method of producing an aqueous dispersion of acid-modified polypropylene resin, for example, heating in a container capable of sealing an acid-modified polypropylene resin and an aqueous medium (containing an organic solvent, a basic compound, etc. as required) Methods of stirring and the like are known. However, since the acid-modified polypropylene resin in the present invention is a homopolypropylene having an isotactic structure as the polypropylene component, it has a high crystallinity and a high melting point, and it can be used for chemicals such as acids, alkalis, organic solvents, and water. It is difficult to disperse in water because it is stable. In particular, it has been more difficult to make the number average particle size of the obtained aqueous dispersion within the preferred range. Therefore, in the present invention, among such methods, it is preferable to adopt a manufacturing method described later. Below, the preferable manufacturing method in this invention is demonstrated concretely.

  As an apparatus used for aqueous dispersion, a container used as a solid / liquid stirring apparatus or an emulsifying machine can be used, and it is preferable to use an apparatus capable of applying a pressure of 0.1 MPa or more. The method of agitation and the rotational speed of agitation are not particularly limited, but agitation may be slow as long as the acid-modified polypropylene resin is suspended in an aqueous medium. Therefore, high-speed stirring (for example, 1000 rpm or more) and use of a homogenizer are not essential, and the production of an aqueous dispersion is possible with a simple device.

Raw materials such as an acid-modified polypropylene resin, a basic compound, an organic solvent and water are charged into the above-described apparatus, and are preferably mixed at a temperature of 40 ° C. or less. Then, while maintaining the temperature in the tank at a temperature of 80 to 240 ° C., preferably 100 to 220 ° C., more preferably 110 to 200 ° C., particularly preferably 100 to 190 ° C., stirring is continued until preferably coarse particles disappear (E.g., 5 to 300 minutes).
In the above steps, when the temperature in the tank is less than 80 ° C., the aqueous dispersion of the acid-modified polypropylene resin is difficult to progress, while when the temperature in the tank exceeds 240 ° C., the acid-modified isotactic polypropylene resin Molecular weight may decrease.

In the steps up to this point, the acid-modified polypropylene resin is approximately dispersed in the aqueous medium. However, in the present invention, in order to make the dispersion of the acid-modified polypropylene resin better and to bring the number-average particle diameter of the acid-modified polypropylene resin into the preferable range defined in the present invention, It is preferable to add at least 1 sort (s) chosen from a basic compound, an organic solvent, and water, and to heat (rewarming) and stir again under a temperature of 100-240 degreeC in a sealed container. As described above, by adding the constituent of the aqueous medium and heating and stirring again, the degree of dispersion of the acid-modified polypropylene resin in the aqueous dispersion is adjusted to the preferred range of the number average particle size and the particle size distribution. be able to.
In the reheating process, when the temperature in the tank is less than 100 ° C., the aqueous dispersion of the acid-modified polypropylene resin is difficult to progress, while when the temperature in the tank exceeds 240 ° C., the acid-modified polypropylene resin Molecular weight may decrease.
The method of additionally blending the basic compound, the organic solvent, and the water is not particularly limited, but a method of blending under pressure using a gear pump or the like, a method of blending once after the system internal temperature is once reduced and so on There is.
The ratio of the basic compound to be additionally compounded, the organic solvent, and water may be appropriately determined according to the desired solid concentration, particle diameter, degree of dispersion, and the like. In addition, the total of the basic compound, the organic solvent, and water is preferably adjusted so that the solid content concentration after compounding is 1 to 50% by mass, and more preferably 2 to 45% by mass, and 3 to 3%. An amount of 40% by mass is particularly preferred.

When the above organic solvent is used at the time of production of the aqueous dispersion, after aqueous dispersion, part or all of the organic solvent is distilled out of the system by a desolvent treatment generally called "stripping", May be reduced. It is preferable from the viewpoint of the stability of the aqueous dispersion that the organic solvent content in the aqueous dispersion be 50% by mass or less by stripping.
In the stripping step, substantially all of the organic solvent used for the aqueous dispersion can be distilled off. However, in order to distill off substantially all the organic solvent, it is necessary to increase the degree of vacuum of the device or to extend the operation time, and in view of productivity, the lower limit of the organic solvent content is 0.01 mass. About% is preferable.
As a method of stripping, there is a method of heating while stirring the aqueous dispersion under normal pressure or reduced pressure and distilling off the organic solvent. In addition, since the solid content concentration is increased by distilling off the aqueous medium, for example, when the viscosity is increased and the workability is decreased, water is previously added to the aqueous dispersion. It is also good.

  The solid concentration of the aqueous dispersion can be adjusted by distilling off the organic solvent by such stripping or diluting with an aqueous medium.

  The above method makes it possible to aqueous disperse the acid-modified polypropylene resin in an aqueous medium with little or no undispersed resin remaining. However, in order to remove foreign matter in the container and a small amount of undispersed resin, a filtration step may be provided when the aqueous dispersion is discharged from the apparatus. Although the filtration method is not limited, for example, a method of pressure filtration (for example, air pressure 0.5 MPa) with a stainless steel filter (wire diameter 0.035 mm, plain weave) of 300 mesh may be mentioned. By providing such a filtration step, it is possible to remove any foreign matter or undispersed resin even when they are present, so the aqueous dispersion obtained can be used without problems as an anchor coating agent for polypropylene resin extrusion lamination. Can.

  In the anchor coating agent of the present invention, in order to further improve the performance according to the purpose, resins other than acid-modified polypropylene resin (hereinafter sometimes referred to as "other resins"), crosslinking agents, inorganic particles, pigments And additives such as dyes can be added.

  Examples of other resins to be added to the anchor coating agent of the present invention include polyethylene resin, polyurethane resin, polyester resin, polyvinyl acetate, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyvinyl chloride, ethylene- ( (Meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester-maleic anhydride copolymer, styrene-maleic acid resin, styrene-butadiene resin, butadiene resin, acrylonitrile-butadiene resin, poly (meth) acrylonitrile resin, Examples thereof include (meth) acrylamide resins, chlorinated polyethylene resins, chlorinated polypropylene resins, modified nylon resins, tackifying resins such as rosins and terpenes, phenol resins, silicone resins, epoxy resins and the like. A plurality of things may be mixed and used as needed.

  After applying and drying the anchor coating agent of the present invention on a thermoplastic resin film substrate, the laminate obtained by extrusion lamination of a polypropylene resin is folded to form a packaging material, to which contents such as oil or volatile substance are added. When it is enclosed and stored, delamination may occur at the folds. However, the occurrence of such delamination can be suppressed by adding a polyethylene resin, a polyurethane resin, and a polyester resin to the anchor coating agent. The addition amount of the polyethylene resin, the polyurethane resin and the polyester resin is preferably 1 to 100 parts by mass, and more preferably 5 to 60 parts by mass with respect to 100 parts by mass of the acid-modified polypropylene resin in the aqueous dispersion. . When adding polyethylene resin, polyurethane resin, polyester resin, etc. to the aqueous dispersion of acid-modified polypropylene resin, use an aqueous dispersion of each resin, which does not contain a non-volatile aqueous dispersion aid. However, since it is excellent in the effect which suppresses the delamination of the crease part of a packaging material, it is preferable.

  The polyethylene resin preferably added to the anchor coating agent of the present invention is more preferably an acid-modified polyethylene resin, and particularly preferably an acid-modified polyethylene resin having an unsaturated carboxylic acid content of 1 to 5% by mass. preferable. Specific examples of the acid-modified polyethylene resin include ethylene- (meth) acrylic acid ester-maleic anhydride copolymers in which the content of unsaturated carboxylic acid is 1 to 5% by mass.

The polyurethane resin preferably added to the anchor coat agent of the present invention is a polymer containing a urethane bond in the main chain, and is obtained, for example, by the reaction of a polyol compound and a polyisocyanate compound.
The polyurethane resin preferably has an anionic group from the viewpoint of adhesiveness and dispersibility in an aqueous medium. The anionic group is a functional group which 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.
The polyurethane resin is preferably a polycarbonate-type polyurethane resin, a polyether-type polyurethane resin, or a polyester-type polyurethane resin from the viewpoint of suppressing the delamination of the fold portion of the packaging material, and the polycarbonate-type polyurethane resin and the polyether-type polyurethane resin are more preferable. Polyether-type polyurethane resins are particularly preferred.
The polyurethane resin in the present invention may be either of two-pack type or one-pack type. However, from the viewpoint of a long pot life and excellent workability at the time of use, the one-pack type is preferable.
The two-component polyurethane resin is a mixture of a main component mainly composed of a polyol component and a curing agent mainly composed of an isocyanate component immediately before use (up to about 12 hours before use) from the viewpoint of pot life. The polyurethane resin used is a type in which the polyol component in the main agent and the isocyanate component in the curing agent react with film evaporation to form a film.
The one-component polyurethane resin is a polyurethane resin that has a long pot life and does not require mixing a plurality of components immediately before use, and is a type that forms a film even if the medium is only evaporated .

  The polyester resin preferably added to the anchor coat agent of the present invention is a polymer having a polybasic acid component and a polyhydric alcohol component as main components. The polyester resin may be copolymerized with monocarboxylic acid, monoalcohol and hydroxycarboxylic acid.

The crosslinking agent to be added to the anchor coating agent of the present invention includes a crosslinking agent having self-crosslinking ability, a crosslinking agent having a plurality of functional groups reactive with carboxyl groups in the molecule, and a metal complex having a polyvalent coordination site. Etc. can be used.
Specifically, oxazoline type crosslinking agents, isocyanate type crosslinking agents (including block type), amine type crosslinking agents, carbodiimide type crosslinking agents, melamine type crosslinking agents, urea type crosslinking agents, epoxy type crosslinking agents, zirconium salt compounds, A silane coupling agent, an organic peroxide, etc. are mentioned.
Among them, a crosslinking agent having a plurality of functional groups that react with carboxyl groups in the molecule is more preferable. As such a crosslinking agent, an oxazoline type crosslinking agent, a carbodiimide type crosslinking agent, an epoxy type crosslinking agent, an isocyanate type crosslinking agent, an amine type crosslinking agent, a melamine type crosslinking agent, etc. are mentioned. A plurality of these may be used in combination. Among them, the addition of an oxazoline-based crosslinking agent or a carbodiimide-based crosslinking agent is preferable from the viewpoint of suppressing the delamination of the folds in the packaging material.
The addition amount of the oxazoline crosslinking agent and the carbodiimide crosslinking agent is preferably 0.1 to 20 parts by mass, and preferably 1 to 10 parts by mass with respect to 100 parts by mass of the acid-modified polypropylene resin in the aqueous dispersion. Is more preferred.

  Inorganic particles to be added to the anchor coating agent of the present invention include metal oxides such as magnesium oxide, zinc oxide and tin oxide, inorganic particles such as calcium carbonate and silica, vermiculite, montmorillonite, hectorite, hydrotalcite, Layered inorganic compounds such as synthetic mica and the like can be mentioned. The average particle diameter of these inorganic particles is preferably 0.005 to 10 μm, and more preferably 0.005 to 5 μm, from the viewpoint of the stability of the aqueous dispersion. A plurality of inorganic particles may be mixed and used. Zinc oxide can be used for ultraviolet shielding and tin oxide can be used for antistatic purposes.

Examples of pigments and dyes to be added to the anchor coating agent of the present invention include titanium oxide, zinc flower, carbon black and the like, and any of disperse dyes, acid dyes, cationic dyes, reactive dyes, etc. can be used. It is.
The anchor coating agent of the present invention further contains various agents such as a leveling agent, an antifoaming agent, an anti-slip agent, a pigment dispersant, an ultraviolet light absorber, a thickener, a weathering agent, a flame retardant and the like as necessary. It is also possible.

  The additives as described above may be used alone or in combination of two or more. The additive is preferably water-soluble or water-dispersible from the viewpoint of ease of addition to the anchor coating agent and mixing.

  The anchor coat agent of the present invention is applicable to the whole packaging material obtained by the method of extrusion laminating the polypropylene resin through the anchor coat layer after applying and drying on the substrate to form the anchor coat layer. The configuration of the packaging material is not particularly limited as long as this method can be applied, but in the present invention, the effects of the present invention are preferably exhibited by using the packaging material described below.

Next, the packaging material of the present invention will be described.
The packaging material of the present invention is a packaging material comprising a thermoplastic resin film layer, an anchor coat layer, and an extruded polypropylene resin layer laminated at least in this order, and the anchor coat layer is obtained from the anchor coat agent of the present invention. Coating film.

  As a film used for a thermoplastic resin film layer, the film manufactured by using various thermoplastic resins as a raw material can be used. Examples of thermoplastic resins include polyester resins such as polyethylene terephthalate (hereinafter sometimes referred to as "PET"), polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, and mixtures thereof; polycapronamide (nylon 6) , Polyamide resins such as polyhexamethylene adipamide (nylon 66), poly-p-xylylene adipamide (MXD6 nylon), and mixtures thereof; polyolefin resins such as polyethylene, polypropylene, and mixtures thereof Can be mentioned. Among these, polyester resins and polyolefin resins excellent in mechanical properties when used as a packaging material are preferable, and among these, polyethylene terephthalate and polypropylene are more preferable.

  The thermoplastic resin film may be one produced by a generally known method, and may be either a non-oriented film or a stretched film, but uniaxially or biaxially stretched from the viewpoint of imparting transparency and glossiness A film is preferred, and a biaxially stretched film is more preferred. The thickness of the film is not particularly limited, and usually 5 to 500 μm is used.

  In the thermoplastic resin film, it is preferable that the surface on which the anchor coat layer is provided be subjected to surface activation treatment in order to improve adhesion. The surface activation treatment includes, for example, corona discharge treatment, flame plasma treatment, atmospheric pressure plasma treatment, low pressure plasma treatment, ozone treatment, electron beam irradiation treatment, ultraviolet irradiation treatment, chemical treatment, solvent treatment, etc. From the balance of the adhesion effect, corona discharge treatment is preferred.

  The anchor coat layer is a coating film formed by applying and drying the anchor coat agent of the present invention on at least one side of a thermoplastic resin film. By having the anchor coat layer, the thermoplastic resin film layer and the extruded polypropylene resin layer can be adhered well, and the effects of the present invention are exhibited.

  The anchor coat layer is a known method such as gravure roll coating, reverse roll coating, wire bar coating, lip coating, air knife coating, curtain flow coating, spray coating, dip coating, brush coating, etc. Uniformly coat the thermoplastic resin film surface, and if necessary, set at around room temperature, subject to drying treatment or heat treatment for drying, and uniform by drying part or all of the aqueous medium The coating film can be formed in close contact with the surface of the thermoplastic resin film layer.

  In the thermoplastic resin film layer, a barrier layer or other layer to be described later is laminated on one of the surfaces in advance before forming the anchor coat layer, and then at least a part of the other surface, It is possible to apply and dry the anchor coating agent.

The amount of anchor coat layer, the area of the coated surface, it is preferable that a dry weight is 0.001 to 5 g / ^{m 2,} more preferably from 0.01 to 3 g / ^{m 2,} 0.02 further preferably to 2 g / ^{m 2,} particularly preferably from 0.03~1g / ^{m 2,} and most preferably 0.05 to 0.5 g / ^{m 2.} When the amount of the anchor coat layer is less than 0.001 g / m ² , sufficient adhesiveness and resistance to content property tend not to be obtained, while when it exceeds 5 g / m ² , it tends to be economically disadvantageous. It is in.

  At the time of drying after coating the anchor coating agent, it is preferable to dry all of the aqueous medium from the viewpoint of improving adhesion and resistance to content. The drying conditions are not particularly limited, but may be suitably selected in the range of 40 to 200 ° C. as the drying temperature and in the range of 1 to 600 seconds as the drying time, in consideration of the drying property and the performance.

  The laminate in which the anchor coat layer is laminated on the thermoplastic resin film by the above method may be subjected directly to in-line extrusion lamination as described later, or after being wound once on a roll, it is extruded while being unwound. You may use for a process.

  The extruded polypropylene resin layer is a resin layer formed by extruding and laminating a polypropylene resin on the anchor coat layer on the thermoplastic resin film layer, and usually serves as a sealant layer.

  Types of polypropylene resin used for extrusion lamination include homopolypropylene, random polypropylene, polypropylene resin such as terpolymer, acid-modified polypropylene resin, polypropylene copolymer containing 50% by mass or more of propylene monomer as a copolymerization component, etc. Can be mentioned. These may be any of an isotactic structure, a syndiotactic structure, and an atactic structure.

  As a method of forming an extruded polypropylene resin layer, the anchor coat agent of the present invention is applied to at least one surface of a thermoplastic resin film layer and dried to form an anchor coat layer, and then on the anchor coat layer, The method of extrusion laminating the molten polypropylene resin is mentioned. Immediately after extruding and laminating the molten polypropylene resin, it is preferable to provide a cooling roll to solidify by cooling. The temperature of the molten polypropylene resin at the time of extrusion is preferably 180 to 400 ° C., more preferably 200 to 300 ° C., more preferably 220 to 280 ° C. from the viewpoint of improving adhesion and resistance to content. Particular preference is given to ° C. The molten polypropylene resin during extrusion may be subjected to treatment such as ozone treatment. Moreover, in the case of extrusion lamination, you may use together the sand lamination method and the co-extrusion lamination method for the purpose of providing another layer further inside the extrusion polypropylene resin layer. The inner side in the packaging material means the surface (inner surface) on the side of encapsulating the contents when the laminate obtained by extrusion lamination is used as the packaging material, and the outer side is the other side thereof. It is a face (outer surface).

  The line speed at which the polypropylene resin is extrusion laminated (the winding speed of the laminated laminate) is preferably 100 to 600 m / min, more preferably 120 to 500 m / min, and 150 to 400 m / min. More preferably, it is minutes. If the line speed is less than 100 / min, the productivity is low, the PP odor tends to increase, and if it exceeds 600 m / min, laminating becomes difficult.

In the packaging material of the present invention, a barrier layer is preferably laminated further outside the thermoplastic resin film layer. By laminating the barrier layer, the wetness and oxidation of the contents can be suppressed, and the contents can be retained well.
The barrier layer may be made of any material that can block liquid or gas. The barrier property may be appropriately set in an optimum range according to the contents to be packaged, the storage period, etc., and generally, the water vapor permeability is preferably 100 g / m ² · day (40 ° C, 90% RH) or less 20 g / m ² · day or less is more preferable, 10 g / m ² · day or less is more preferable, and 1 g / m ² · day or less is particularly preferable. Oxygen as the ^{permeability, 100ml / m 2 · day ·} MPa (20 ℃, 90% RH) is preferably less, 20 ml ^/ m, more preferably less ^{2 · day · MPa, 10ml /} m 2 · day · MPa or less is more Preferably, 1 ml / m ² · day · MPa or less is particularly preferable.
Specific examples of the barrier layer include soft metal foils such as aluminum foil, vapor deposited layers such as aluminum vapor deposition, silica vapor deposition, alumina vapor deposition, and silica alumina binary vapor deposition, and further vinylidene chloride resin, modified polyvinyl alcohol, ethylene vinyl An organic barrier layer made of alcohol copolymer, MXD nylon or the like can be employed. Among them, vapor deposition layers such as aluminum vapor deposition, silica vapor deposition, alumina vapor deposition, and silica alumina binary vapor deposition are preferable because they are inexpensive and excellent in barrier properties, and aluminum vapor deposition is particularly preferable from the viewpoint of concealability. A protective coating layer may be provided on the vapor deposition layer.

The packaging material of the present invention has durability and rigidity (for example, impact resistance and pinhole resistance), necessary physical properties (for example, ease of tearing and hand cut), adhesion between layers, designability and the like. In consideration of the performance required as a packaging material, etc., other than the above barrier layer, thermoplastic resin film layer, anchor coat layer, and extruded polypropylene resin layer, other materials such as film substrate, printing, paper, non-woven fabric, etc. The layers may be laminated on the inner side, the outer side and between each layer as long as the effects of the present invention are not impaired.
The type of the film substrate is not limited, and the same material as the thermoplastic resin film layer or the barrier layer may be used. In addition, an adhesive layer may be provided between the other layers and laminated by a known method. As the adhesive, it is possible to use a one-component urethane adhesive, a two-component urethane adhesive, an epoxy adhesive, an aqueous dispersion of an acid-modified polyolefin, or the like. In addition, the anchor coating agent of the present invention may be used for adhesion of other layers.
These other layers may contain known additives and stabilizers, such as an antistatic agent, an easy-adhesion coating agent, a plasticizer, a lubricant, an antioxidant and the like, and the adhesion when laminated with other materials The surface may be pretreated with corona treatment, plasma treatment, ozone treatment, chemical treatment, solvent treatment, etc. to improve the
The thickness of the other layer may be determined in consideration of the suitability as a packaging material and the processability in the case of laminating, and is not particularly limited, but in the practical range of 1 to 300 μm, depending on the application, 300 μm or more You can adopt the

  It does not specifically limit as an aspect of the packaging material of this invention. Three-sided sealed bag, four-sided sealed bag, gusset packaging bag, pillow packaging bag, Goebel top type bottomed container, tetra classic, black type, tube container, paper cup (produce the blank plate of the body and bottom, the blank plate There are various types such as a cylindrical body with a cup forming machine, a paper cup container formed by molding the bottom at one open end of the body and heat bonding, etc.), a lid material, etc. A zipper made of polypropylene resin may be provided to make a packaging bag with a chuck.

  The packaging material of the present invention has good resistance to the contents containing oil and volatile substances, and can accelerate the speed of the production line (line speed when laminating polypropylene resin by extrusion lamination). It is suitable for packaging materials for snacks, since it is possible. Furthermore, since it becomes possible to suppress PP odor and does not impair the flavor of potato snacks such as potato chips, it is most suitable for a packaging material for potato snacks. Here, potato snacks are snacks mainly composed of potatoes, and potato chips are potato chips prepared by slicing raw potatoes after being cooked, mashed potatoes made by heating cooked raw potatoes, and dried potato raw materials. Among the dried potato granules, dried mashed potatoes, and dried potato flakes, water is optionally added to one or more kinds thereof, and the mixture is kneaded to form a dough, which is then die-cut and shaped and cooked. In addition, before shape-cooking the dough after die-cutting, what provided the drying process may be used.

  The packaging material of the present invention is excellent in the adhesiveness between the thermoplastic resin film layer and the extruded polypropylene resin layer adhered via the anchor coat layer. The adhesion between the thermoplastic resin film layer and the extruded polypropylene resin layer is preferably 1 N / 15 mm or more, more preferably 2 N / 15 mm or more, particularly preferably 3 N / 15 mm or more, and 4 N / 15 mm or more. More preferably, 5 N / 15 mm or more is the most preferable. In addition, the packaging material of the present invention preferably has a high adhesive strength retention rate even if it contains an oil or a content containing a volatile substance, and has the adhesiveness as described above. Is more preferred.

  The present invention will be specifically described by way of the following examples. However, the present invention is not limited by these.

1. Properties of acid-modified polypropylene resin (1) Composition, structure and mismatch rate of acid-modified polypropylene resin
^It calculated | required from the <1> H-NMR analyzer (Nihon Denshi make, ECA500, 500 MHz). The measurement was carried out at 120 ° C. using tetrachloroethane (d ₂ ) as a solvent.

(2) Residual amount of unreacted unsaturated carboxylic acid component of acid-modified polypropylene resin Approximately 0.05 g of acid-modified polypropylene resin is precisely weighed, 20 ml of methanol is used as an extraction solvent, and extraction is performed at room temperature for 21 hours by continuous inversion mixing. The The extract was filtered with a disk filter (pore diameter 0.45 μm), and the filtrate was subjected to high performance liquid chromatography (HP1100 manufactured by Hewlett Packard, Puresil 5 μ C18 120 Å φ4.6 mm × 250 mm (40 ° C.) manufactured by Waters). It quantified.
When the amount of unreacted unsaturated carboxylic acid monomer component remaining was less than 1000 ppm, the amount of acid-modified polypropylene resin pellets was changed to 0.5 g and quantified similarly.
A calibration curve was prepared using maleic anhydride standard samples of known concentration.

(3) Melt flow rate (MFR) of acid-modified polypropylene resin
It measured by 170 degreeC and 2160 g load according to the method of JISK 7210: 1999.
(4) Melting | fusing point of acid-modified polypropylene resin It measured by DSC method using Perkin-Elmer DSC7.

2. Properties of anchor coating agent for extrusion extrusion lamination of polypropylene resin (1) Number average particle diameter of dispersed particles in aqueous dispersion Microtrac particle size distribution meter (manufactured by Nikkiso Co., Ltd., UPA 150, MODEL No. 9340, dynamic light scattering method) I asked for. The refractive index of the resin used for particle diameter calculation was 1.50.

3. Properties of Packaging Material (1) Laminate Strength From around the center of the 80 mm side of the packaging material obtained in each example, a test piece is cut out with a width of 15 mm parallel to the 100 mm side, and a tensile tester (Intesco's precision universal material test Machine required to peel off the interface between the thermoplastic resin film layer of the test piece and the extruded polypropylene resin layer under the conditions of a tensile speed of 200 mm / min. Was measured by a T-peel test. The measurement was carried out with 10 samples, and the average value was taken as the laminate strength.

(2) Laminate strength after content resistance test (content resistance test 1)
The packaging material obtained in each example was charged with 12 g of Nisshin Oillio-made salad oil (canola oil) as a content, air was removed, and sealed by heat sealing. In the case of heat sealing, it sealed so that air might not enter into packaging material. The packaging material sealed with this salad oil was stored at 50 ° C. for 2 weeks. Thereafter, except for the contents, the laminate strength was measured in the same manner as the above (1). The measurement was performed with 10 samples, and the average value was taken as the laminate strength after the content resistance test.

(3) Evaluation of creases after content resistance test (content resistance test 2)
A packaging material sealed with salad oil was prepared in the same manner as (2) above, and stored at 50 ° C. for 2 weeks. Thereafter, the heat-sealed portion of the packaging material was cut off and the contents were removed, and then the packaging material was spread, and the presence or absence of delamination of the portion positioned at the fold of the packaging material was visually confirmed. The measurement was carried out with 10 samples, and was evaluated by the number of delaminated samples out of 10 samples.
From the viewpoint of practical use, the number of samples having delamination in this evaluation is preferably 5 or less, more preferably 3 or less, still more preferably 2 or less, particularly preferably 1 or less, and most preferably 0.

(4) Evaluation of PP odor The degree of PP odor inside the packaging material obtained in each example was evaluated by a panelist of experienced odor according to the following three-step relative comparison. In addition, in the case of evaluation 1, even if it encloses potato snacks, there is no unpleasant smell, there is no bad influence on the flavor of potato snacks, and in the case of evaluation 2, when you enclose potato snacks, slightly unpleasant smell However, it is a level that does not adversely affect the flavor of potato snacks in practical use, that is, a practical level, and in the case of rating 3, the inclusion of potato snacks causes unpleasant odor, and the flavor of potato snacks in practical use is adversely affected. , Which is the level that matters.
Evaluation 1: PP odor is small Evaluation 2: PP odor is medium evaluation 3: PP odor is large

[Preparation of acid-modified polypropylene resin]
Preparation Example 1 (Production of Acid-Modified Polypropylene Resin “PP1”)
A polypropylene obtained by subjecting a homopolypropylene resin having an isotactic structure (MFR = 0.1 g / 10 min-170 ° C. · 2,160 g) to 360 ° C. × 80 min thermal decomposition treatment under nitrogen gas flow under normal pressure. 1000 g of the resin was put in a jacketed reactor, purged with nitrogen, heated to 180 ° C. to melt, and then 125 g of maleic anhydride was added and uniformly mixed. Thereto, 125 g of xylene in which 6.3 g of dicumyl peroxide was dissolved was dropped, and the mixture was reacted by stirring at 180 ° C. for 3 hours. Thereafter, xylene was distilled off under reduced pressure, and the obtained reaction product was poured into 3 kg of acetone to solidify the resin. The resin was cut into small pieces and processed into pellets. This pellet-like resin was called "base resin".
100 g of this base resin was mixed with 300 g of acetone, and the resin was washed by stirring for 1 hour while being kept at 50 ° C. After recovering the resin from the washing solution, the same method was repeated twice to wash the resin. After the resin is recovered from the washing solution, this resin is further mixed with 300 g of a washing solution (acetone / dimethylaminoethanol = 90/10 (mass ratio)) consisting of acetone and dimethylaminoethanol, and stirred at 50 ° C. for 1 hour The resin was washed to remove free maleic anhydride. The resin was dried under reduced pressure in a reduced pressure drier to obtain an acid-modified polypropylene resin “PP1”.

Preparation Example 2 (Production of Acid-Modified Polypropylene Resin “PP2”)
100 g of the base resin obtained in Preparation Example 1 was mixed with 300 g of acetone, and the resin was washed by stirring for 1 hour while being kept at 50 ° C. After recovering the resin, the resin was further washed in the same manner. After recovering the resin, this resin is further mixed with 300 g of a washing solution consisting of acetone and dimethylaminoethanol [acetone / dimethylaminoethanol = 90/10 (mass ratio)], and stirred at 50 ° C. for 1 hour for resin Was washed. After recovery of the resin, the resin was washed by the same method (using a washing solution consisting of acetone and dimethylaminoethanol) to remove free maleic anhydride. The resin was dried under reduced pressure in a reduced pressure drier to obtain an acid-modified polypropylene resin "PP2".

Preparation Example 3 (Production of Acid-Modified Polypropylene Resin “PP3”)
100 g of the base resin obtained in Preparation Example 1 was mixed with 300 g of acetone, and the resin was washed by stirring for 1 hour while being kept at 50 ° C. After recovering the resin, this resin is further mixed with 300 g of a washing solution consisting of acetone and dimethylaminoethanol [acetone / dimethylaminoethanol = 90/10 (mass ratio)], and stirred at 50 ° C. for 1 hour for resin Was washed. After the resin was recovered, the resin was washed twice by repeating the same method (a method using a washing solution consisting of acetone and dimethylaminoethanol) twice to remove free maleic anhydride. The resin was dried under reduced pressure in a reduced pressure drier to obtain an acid-modified polypropylene resin "PP3".

Preparation Example 4 (Production of Acid-Modified Polypropylene Resin “PP4”)
The same operation as in Preparation Example 3 was carried out except that the temperature 50 ° C. was changed to 80 ° C. at the time of washing with acetone and washing with acetone and a washing solution consisting of dimethylaminoethanol, to obtain an acid-modified polypropylene resin “PP4”. The

Preparation Example 5 (Production of Acid-Modified Polypropylene Resin “PP5”)
The same procedure as in Preparation Example 3 was carried out except that the temperature 50 ° C. was changed to 85 ° C. at the time of washing with acetone and washing with acetone and a washing solution consisting of dimethylaminoethanol, to obtain an acid-modified polypropylene resin “PP5”. The

Preparation Example 6 (Production of Acid-Modified Polypropylene Resin “PP6”)
100 g of the base resin obtained in Preparation Example 1 was mixed with 300 g of acetone, and the resin was washed by stirring for 1 hour while being kept at 50 ° C. After recovering the resin, the same procedure was repeated three more times to wash the resin to remove free maleic anhydride. The resin was dried under reduced pressure in a reduced pressure drier to obtain an acid-modified polypropylene resin "PP6".

Preparation Example 7 (Production of Acid-Modified Syndiotactic Polypropylene Resin "PP7")
A polypropylene obtained by subjecting a homopolypropylene resin having a syndiotactic structure (MFR = 0.1 g / 10 min-170 ° C., 2160 g) to 360 ° C. × 80 minutes thermal decomposition treatment under nitrogen gas flow at normal pressure. 1000 g of the resin was put in a jacketed reactor, purged with nitrogen, heated to 180 ° C. to melt, and then 125 g of maleic anhydride was added and uniformly mixed. Thereto, 125 g of xylene in which 6.3 g of dicumyl peroxide was dissolved was dropped, and the mixture was reacted by stirring at 180 ° C. for 3 hours. Thereafter, xylene was distilled off under reduced pressure, and the obtained reaction product was poured into 3 kg of acetone to solidify the resin. The resin was cut into small pieces and processed into pellets.
100 g of this pellet-like resin was mixed with 300 g of acetone, and the resin was washed by stirring for 1 hour while being kept at 50 ° C. After recovering the resin, this resin is further mixed with 300 g of a washing solution consisting of acetone and dimethylaminoethanol [acetone / dimethylaminoethanol = 90/10 (mass ratio)], and stirred at 50 ° C. for 1 hour for resin Was washed. After the resin was recovered, the resin was washed twice by repeating the same method (a method using a washing solution consisting of acetone and dimethylaminoethanol) twice to remove free maleic anhydride. The resin was dried under reduced pressure in a reduced pressure drier to obtain an acid-modified syndiotactic polypropylene resin "PP7".

Preparation Example 8 (Production of acid-modified isotactic (random) polypropylene resin "PP8")
As a polypropylene resin, a random polypropylene of isotactic structure (propylene / ethylene = 95/5 (mass%), MFR = 0.1 g / 10 min.-170 ° C., 2160 g) in place of a homopolypropylene resin of syndiotactic structure The same operation as in Preparation Example 7 was performed, except that a random polypropylene resin “PP8” having an acid-modified isotactic structure was obtained.

Preparation Example 9 (Production of Acid-Modified Isotactic (Block) Polypropylene Resin "PP9")
As a polypropylene resin, a block polypropylene resin having an isotactic structure (propylene / ethylene = 95/5% by mass, MFR = 0.2 g / 10 minutes-170 ° C., 2160 g) instead of a homopolypropylene resin having a syndiotactic structure is used. The same operation as in Preparation Example 7 was performed except for using, to obtain a block polypropylene resin "PP9" having an acid-modified isotactic structure.

Preparation Example 10 (Production of acid-modified isotactic (ter) polypropylene resin "PP10")
1000 g of a polypropylene terpolymer of isotactic structure (propylene / ethylene / butene = 64.8 / 11.3 / 23.9 (% by mass, MFR = 0.3 g / 10 min-170 ° C. · 2160 g)) The reactor was placed in a jacketed reactor, purged with nitrogen, heated to 180 ° C. and melted, and then 110 g of maleic anhydride was added and uniformly mixed. Thereto, 4.0 g of dicumyl peroxide was dropped, and the mixture was reacted by stirring at 180 ° C. for 3 hours. After completion of the reaction, the obtained reaction product was poured into 3 kg of acetone to solidify the resin. The resin was cut into small pieces and processed into pellets.
100 g of this pellet-like resin was mixed with 300 g of acetone, and the resin was washed by stirring for 1 hour while being kept at 50 ° C. After recovering the resin, this resin is further mixed with 300 g of a washing solution consisting of acetone and dimethylaminoethanol [acetone / dimethylaminoethanol = 90/10 (mass ratio)], and stirred at 50 ° C. for 1 hour for resin Was washed. After the resin was recovered, the resin was washed twice by repeating the same method (a method using a washing solution consisting of acetone and dimethylaminoethanol) twice to remove free maleic anhydride. This resin was dried under reduced pressure in a reduced pressure drier to obtain terpolypropylene (terpolymer) resin "PP10" having an acid-modified isotactic structure.

  The characteristics of the acid-modified polypropylene resin (PP1 to PP10) are shown in Table 1.

Example 1
<Manufacture of anchor coating agent>
75.0 g of acid-modified polypropylene resin “PP1”, 30.0 g of isopropanol, 170.0 g of tetrahydrofuran, 15.0 g of dimethylaminoethanol using a stirrer equipped with a sealable pressure resistant 1 L glass container with a heater And when 210.0 g of distilled water was charged in a glass container and stirred at a rotational speed of a stirring blade of 300 rpm, no resin precipitation was observed at the bottom of the container and it was confirmed that it was in a floating state. Then, while maintaining this state, the heater was turned on and heated after 10 minutes. Then, the temperature inside the system was kept at 150 ° C., and after stirring for additional 60 minutes, the power of the heater was turned off and natural cooling was carried out.
When the internal temperature cooled to 80 ° C., the container was opened, and a raw material consisting of 60.0 g of tetrahydrofuran, 10.0 g of dimethylaminoethanol and 50.0 g of distilled water was additionally charged. After that, the container was sealed, the power of the heater was turned on, and the stirring blade was again heated (reheated) at a rotational speed of 300 rpm. After the system temperature was maintained at 140 ° C. and the stirring was continued for additional 60 minutes, the output of the heater was adjusted to an internal temperature of 80 ° C.
When the internal temperature cooled to 80 ° C., the system was gradually depressurized using a vacuum pump to remove isopropanol, tetrahydrofuran and water. After removing 400 g or more of tetrahydrofuran, isopropanol and water, the heater is turned off, and when the system temperature reaches 35 ° C., water is added to make the concentration of “PP1” in the aqueous dispersion 20 mass%. The mixture was adjusted as above and pressure-filtered through a 180-mesh stainless steel filter to obtain a uniform aqueous dispersion of acid-modified polypropylene resin, that is, an anchor coating agent for polypropylene resin extrusion lamination. This aqueous dispersion was called "AC1." In addition, after pressure filtration, the non-dispersed thing of resin was not able to be confirmed on the filter.
<Production of laminates>
As a substrate, a biaxially stretched PET film with a thickness of 12 μm having an aluminum deposition layer on one side is used, and the amount of the anchor coat layer after drying is 0.3 g / m ^{2 on} this PET surface, “AC1” was applied and dried at 100 ° C. for 10 seconds to form an anchor coat layer.
Subsequently, using an extrusion laminating apparatus equipped with a T-die, a polypropylene resin (Novatec PP FL02A, manufactured by Japan Polypropylene Corp.) was melt-extruded on the surface of the anchor coat layer to laminate an extruded polypropylene resin layer having a thickness of 30 μm. At this time, the temperature of the molten polypropylene resin immediately below the T-die was 240.degree. In addition, the line speed of the extrusion laminate (rolling speed of the laminate) was 120 m / min.
In this way, a laminate having the structure of aluminum deposited layer / PET film / anchor coat layer / extruded polypropylene resin layer was obtained.
<Manufacture of packaging materials>
This laminate was cut into a rectangle of 160 mm × 100 mm and folded in half so that the side of 160 mm was half and the extruded polypropylene resin layer was inside (in this case, one side of 100 mm) Becomes a fold, and it becomes a folded 80 mm x 100 mm rectangular laminated body). One side of the 80 mm side of this laminate and the other side of the 100 mm side were heat sealed to a width of 3 mm to obtain a rectangular packaging material of 80 mm × 100 mm.

Examples 2 to 6
<Manufacture of anchor coating agent>
As an acid-modified polypropylene resin used in the preparation of the anchor coating agent in Example 1, "PP2" in Example 2, "PP3" in Example 3, and Example 4 in place of "PP1" An anchor consisting of an aqueous dispersion of a uniform acid-modified polypropylene resin in the same manner as in Example 1 except that “PP4”, “PP5” in Example 5, “PP6” in Example 6 were used. The coating agent was obtained. The aqueous dispersion obtained in Example 2 is “AC2”, the aqueous dispersion obtained in Example 3 is “AC3”, the aqueous dispersion obtained in Example 4 is “AC4”, and the aqueous dispersion obtained in Example 4 is obtained in Example 5 The aqueous dispersion obtained was named "AC5" and the aqueous dispersion obtained in Example 6 was named "AC6". In addition, after filtration of the aqueous dispersion, the undispersed resin could not be confirmed in any of the examples on the filter.
<Production of laminates and packaging materials>
Instead of "AC1" as an anchor coating agent, "AC2" in Example 2, "AC3" in Example 3, "AC4" in Example 4, and "AC5" in Example 5 Then, a laminate and a packaging material were obtained in the same manner as the production of the laminate of Example 1 and the production of the packaging material except that “AC6” was used.

Example 7
<Manufacture of anchor coating agent>
An aqueous dispersion of a uniform acid-modified polypropylene resin was carried out in the same manner as in Example 3, except that the temperature in the system by reheating was changed from 140 ° C. to 110 ° C. in the production of the anchor coating agent in Example 3. The anchor coat agent which consists of body "AC7" was obtained. After filtration of the aqueous dispersion, no undispersed resin could be confirmed on the filter.
<Production of laminates and packaging materials>
A laminate and a packaging material were obtained in the same manner as the production of the laminate of Example 1 and the production of the packaging material except that “AC7” was used instead of “AC1” as the anchor coating agent.

Example 8
<Manufacture of anchor coating agent>
In the production of the anchor coat agent in Example 3, all the raw materials were charged at one time to obtain an aqueous dispersion.
That is, 75.0 g of acid-modified polypropylene resin “PP3”, 30.0 g of isopropanol, 230.0 g of tetrahydrofuran, 25.0 g of dimethyl, using a stirrer equipped with a sealable pressure resistant 1 L glass container with a heater Aminoethanol and 260.0 g of distilled water were charged in a glass container, and the stirring blade was stirred at a rotational speed of 300 rpm. As a result, no precipitation of resin was observed at the bottom of the container, confirming that it was suspended. The Then, while maintaining this state, the heater was turned on and heated after 10 minutes. Then, the temperature inside the system was kept at 150 ° C., and after stirring for additional 60 minutes, the output of the heater was adjusted so that the internal temperature became 80 ° C.
When the internal temperature cooled to 80 ° C., the system was gradually depressurized using a vacuum pump to remove isopropanol, tetrahydrofuran and water. After removing 400 g or more of tetrahydrofuran, isopropanol and water, the heater is turned off, and when the system temperature reaches 35 ° C., water is added to make the concentration of “PP3” in the aqueous dispersion 20 mass%. The mixture was adjusted as above and pressure-filtered through a 180-mesh stainless steel filter to obtain an anchor coat agent for extrusion extrusion lamination of polypropylene resin, which is composed of a uniform aqueous dispersion of acid-modified polypropylene resin "AC 8". In addition, the non-dispersed thing of resin was confirmed on the filter after pressure filtration.
<Production of laminates and packaging materials>
A laminate and a packaging material were obtained in the same manner as in the production of the laminate of Example 1 and the production of the packaging material except that “AC8” was used instead of “AC1” as the anchor coating agent.

Examples 9 to 11
The line speed of 120 m / min for extrusion lamination in the production of the laminate in Example 3 was changed to 160 m / min in Example 9, 500 m / min in Example 10, and 600 m / min in Example 11. A laminate and a packaging material were obtained in the same manner as in the production of the laminate of Example 3 and the production of the packaging material except for the above.

Example 12
<Manufacture of anchor coating agent>
"AC7" is used as an aqueous dispersion of acid-modified polypropylene resin, and the content of unsaturated carboxylic acid is 2.5% by mass as "AC7" as an additive. Ethylene-ethyl acrylate-maleic anhydride co-weight A combined aqueous dispersion (solids concentration 20% by weight, containing no non-volatile aqueous dispersing aid, may hereinafter be denoted as "EAM") was added and mixed. The solid content of the aqueous dispersion of ethylene-ethyl acrylate-maleic anhydride copolymer (ethylene-ethyl acrylate-maleic anhydride co-weight) relative to 100 parts by mass of the acid-modified polypropylene resin contained in "AC7" It added so that it might be 50 mass parts of united | combined.
In this way, an anchor coating agent for polypropylene resin extrusion lamination comprising an aqueous dispersion containing an acid-modified polypropylene resin and an acid-modified polyethylene resin was obtained.
<Production of laminates and packaging materials>
A laminate and a packaging material were obtained in the same manner as in the production of the laminate of Example 1 and the production of the packaging material, except that the anchor coating agent was used instead of “AC1” as the anchor coating agent.

Example 13
<Manufacture of anchor coating agent>
"AC7" is used as an aqueous dispersion of acid-modified polypropylene resin, and "AC7" is an aqueous dispersion of a polyurethane resin as an additive (Adeka Co., Ltd., Adekabon Titer HUX 350, solid concentration 30% by mass, nonvolatile aqueous) An aqueous dispersion of a polyether type polyurethane resin (hereinafter sometimes referred to as "HUX 350") was added and mixed without containing a dispersing aid. The solid content (polyurethane resin) of the aqueous dispersion of the polyurethane resin was added to 50 parts by mass with respect to 100 parts by mass of the acid-modified polypropylene resin contained in "AC7".
In this way, an anchor coating agent for polypropylene resin extrusion lamination comprising an aqueous dispersion containing an acid-modified polypropylene resin and a polyurethane resin was obtained.
<Production of laminates and packaging materials>
A laminate and a packaging material were obtained in the same manner as in the production of the laminate of Example 1 and the production of the packaging material, except that the anchor coating agent was used instead of “AC1” as the anchor coating agent.

Example 14
<Manufacture of anchor coating agent>
“AC7” is used as an aqueous dispersion of acid-modified polypropylene resin, and “AC7” is an aqueous dispersion of a polyester resin as an additive (manufactured by Unitika, Erytel KT-9204, solid concentration 30% by mass, nonvolatile aqueous) A dispersing aid was not included, and may be added and mixed in the following, which may be referred to as "KT 9204". The solid content (polyester resin) of the aqueous dispersion of polyester resin was added to 50 parts by mass with respect to 100 parts by mass of the acid-modified polypropylene resin contained in "AC7".
Thus, an anchor coating agent for polypropylene resin extrusion lamination comprising an aqueous dispersion containing an acid-modified polypropylene resin and a polyester resin was obtained.
<Production of laminates and packaging materials>
A laminate and a packaging material were obtained in the same manner as in the production of the laminate of Example 1 and the production of the packaging material, except that the anchor coating agent was used instead of “AC1” as the anchor coating agent.

Example 15
<Manufacture of anchor coating agent>
"AC7" is used as an aqueous dispersion of acid-modified polypropylene resin, and as "AC7", as an additive, an oxazoline crosslinking agent (Epocross WS700, manufactured by Nippon Shokuhin Co., Ltd., solid content concentration 25% by mass, nonvolatile aqueous dispersion aid) No agent was added, and an aqueous solution of a polyvalent oxazoline compound (hereinafter sometimes referred to as "WS700") was added and mixed. In addition, with respect to 100 mass parts of acid-modified polypropylene resin contained in "AC7", it added so that solid content of an oxazoline type crosslinking agent might be 5 mass parts.
In this way, an anchor coat agent for polypropylene resin extrusion lamination comprising an aqueous dispersion containing an acid-modified polypropylene resin and an oxazoline crosslinking agent was obtained.
<Production of laminates and packaging materials>
A laminate and a packaging material were obtained in the same manner as in the production of the laminate of Example 1 and the production of the packaging material, except that the anchor coating agent was used instead of “AC1” as the anchor coating agent.

Example 16
<Manufacture of anchor coating agent>
"AC7" is used as an aqueous dispersion of acid-modified polypropylene resin, and "AC7" is a carbodiimide-based crosslinking agent (Nisshinbo Chemical Co., Ltd., Carbodilight V-02, solid concentration 40% by mass, non-volatile aqueous dispersion) An aqueous solution of a polyvalent carbodiimide compound (hereinafter sometimes referred to as "V-02") was added and mixed without containing a coagent. In addition, it added so that solid content of a carbodiimide type crosslinking agent might be 5 mass parts with respect to 100 mass parts of acid-modified polypropylene resin contained in "AC7."
Thus, an anchor coat agent for polypropylene resin extrusion lamination comprising an aqueous dispersion containing an acid-modified polypropylene resin and a carbodiimide type crosslinking agent was obtained.
<Production of laminates and packaging materials>
A laminate and a packaging material were obtained in the same manner as in the production of the laminate of Example 1 and the production of the packaging material, except that the anchor coating agent was used instead of “AC1” as the anchor coating agent.

Example 17
In place of the 12 μm thick biaxially stretched PET film having an aluminum deposition layer on one side, which is a base material used in the production of the laminate in Example 3, the aluminum deposition layer is on one side , Using a 20 μm thick biaxially stretched polypropylene film, and forming an anchor coat layer on the biaxially stretched polypropylene film (hereinafter sometimes referred to as “OPP”) surface of the film, except for using the same. The laminate and the packaging material were obtained in the same manner as in the production of the laminate and the production of the packaging material.

Example 18
In the same manner as in the production of the laminate of Example 17 and in the production of the packaging material, except that the line speed of the extrusion laminate in the production of the laminate in Example 17 was changed from 120 m / min to 500 m / min. A laminate and packaging material were obtained.

Examples 19 to 26
Instead of “a 12 μm thick biaxially stretched PET film having an aluminum deposition layer on one side,” which is a base material used in the production of the laminate in Examples 1 to 8, “12 μm thickness on one side” An anchor coat layer is formed on the aluminum foil surface of a 9 μm thick aluminum foil (ie, PET film / dry lamination adhesive / aluminum foil) to which a biaxially stretched PET film is adhered by dry lamination. The laminates and packaging materials of Examples 19 to 26 were obtained in the same manner as in the production of the laminates of Examples 1 to 8 and the production of the packaging materials except for the above. In addition, the structure of the obtained laminated body is a PET film / dry lamination adhesive agent / aluminum foil / anchor coat layer / extrusion polypropylene resin layer.

Comparative Example 1
<Manufacture of anchor coating agent>
75.0 g of acid-modified syndiotactic polypropylene resin “PP7”, 200.0 g of tetrahydrofuran, 15.0 g of dimethylaminoethanol and 210. G using a stirrer equipped with a sealable pressure resistant 1 L glass container with a heater. When 0 g of distilled water was charged in a glass container and the stirring blade was stirred at a rotational speed of 300 rpm, no resin precipitation was observed at the bottom of the container and it was confirmed that the container was in a floating state. Then, while maintaining this state, the heater was turned on and heated after 10 minutes. Then, the temperature inside the system was kept at 130 ° C., and after stirring for additional 60 minutes, the output of the heater was adjusted so that the internal temperature would be 80 ° C.
When the internal temperature had cooled to 80 ° C., the system was gradually depressurized using a vacuum pump to remove tetrahydrofuran and water. After removing 300 g or more of tetrahydrofuran and water, turn off the heater and when the system temperature reaches 35 ° C, add water so that the concentration of “PP7” in the aqueous dispersion becomes 20 mass%. The resultant was adjusted and pressure-filtered through a 180 mesh stainless steel filter to obtain an anchor coat agent composed of a uniform aqueous dispersion of acid-modified syndiotactic polypropylene resin "AC9". After filtration of the aqueous dispersion, no undispersed resin could be confirmed on the filter.
<Production of laminates and packaging materials>
Production and packaging of laminate of Example 1 except using anchor coating agent consisting of "AC9" instead of "AC1" as anchor coating agent, and changing the line speed of the extrusion laminate from 120 m / min to 70 m / min The laminate and the packaging material were obtained in the same manner as the production of the material.

Comparative example 2
<Manufacture of anchor coating agent>
The same method as in Comparative Example 1 except that a random polypropylene resin "PP8" having an acid-modified isotactic structure is used instead of the acid-modified syndiotactic polypropylene resin "PP7" used in the production of an anchor coating agent Thus, an anchor coating agent consisting of an aqueous dispersion "AC10" of a random polypropylene resin having a uniform acid-modified isotactic structure was obtained. After filtration of the aqueous dispersion, no undispersed resin could be confirmed on the filter.
<Production of laminates and packaging materials>
A laminate and a packaging material are obtained in the same manner as the production of the laminate of Comparative Example 1 and the production of the packaging material except that an anchor coating agent consisting of "AC10" is used instead of "AC9" as the anchor coating agent. The

Comparative example 3
By the same method as Example 1 except using block polypropylene resin "PP9" of acid-modified isotactic structure as acid-modified polypropylene resin used in the production of anchor coating agent instead of "PP1" There was obtained an anchor coating agent comprising an aqueous dispersion "AC11" of a block polypropylene resin having a uniform acid-modified isotactic structure. After filtration of the aqueous dispersion, no undispersed resin could be confirmed on the filter.
<Production of laminates and packaging materials>
A laminate and a packaging material are obtained in the same manner as in the production of the laminate of Comparative Example 1 and the production of the packaging material except that an anchor coating agent consisting of "AC11" is used instead of "AC9" as the anchor coating agent. The

Comparative example 4
Comparative Example 1 except that terpolypropylene (terpolymer) resin “PP10” having an acid-modified isotactic structure was used instead of the acid-modified syndiotactic polypropylene resin “PP7” used in the preparation of the anchor coat agent. In the same manner as in the above, an anchor coating agent comprising an aqueous dispersion "AC12" of a terpolypropylene resin having a uniform acid-modified isotactic structure was obtained. After filtration of the aqueous dispersion, no undispersed resin could be confirmed on the filter.
<Production of laminates and packaging materials>
A laminate and a packaging material are obtained in the same manner as in the production of the laminate of Comparative Example 1 and the production of the packaging material except that an anchor coating agent consisting of “AC12” is used instead of “AC9” as the anchor coating agent. The

Comparative Examples 5 to 8
The same as the production of the laminates of Comparative Examples 1 to 4 and the production of the packaging material except that the line speed of the extrusion lamination in the production of the laminates in Comparative Examples 1 to 4 is changed from 70 m / min to 120 m / min. Laminates and packaging materials of Comparative Examples 5 to 8 were obtained by methods.

Comparative Examples 9 to 12
Instead of “a biaxially stretched PET film with a thickness of 12 μm having an aluminum deposition layer on one side,” which is a substrate used in the production of the laminate in Comparative Examples 1 to 4, “an aluminum deposition layer on one side The same as in the production of the laminates of Comparative Examples 1 to 4 and the production of the packaging material except that a 20 μm-thick biaxially stretched OPP film was used and the anchor coat layer was formed on the OPP face thereof. Laminates and packaging materials of Comparative Examples 9 to 12, respectively, were obtained by methods.

Comparative Examples 13 to 16
Instead of “a 12 μm thick biaxially stretched PET film having an aluminum deposition layer on one side”, which is a base material used in the production of a laminate in Comparative Examples 5 to 8, “12 μm thickness on one side” Production of laminates of Comparative Examples 5 to 8 except that an aluminum foil having a thickness of 9 μm in which a biaxially stretched PET film is adhered by dry lamination is used and an anchor coat layer is formed on the aluminum foil surface thereof And the laminated body and packaging material of Comparative Examples 13-16 were obtained by the method similar to manufacture of a packaging material, respectively. In addition, the structure of the obtained laminated body is a PET film / dry lamination adhesive agent / aluminum foil / anchor coat layer / extrusion polypropylene resin layer.

  The properties of the anchor coat agent and the packaging material obtained in Examples 1 to 26 and Comparative Examples 1 to 16 are shown in Tables 2 and 3.

In Examples 1 to 26, an anchor coating agent comprising an aqueous dispersion containing an acid-modified polypropylene resin, which is a homopolypropylene having a isotactic structure, and an aqueous medium has characteristics suitable for extrusion lamination of polypropylene resin. Had.
In particular, in Examples 1 to 18, even when the anchor coating agent was applied to the surface of the thermoplastic resin film, it was confirmed to have excellent properties.
In Examples 1 to 4, 7 and 9 to 11, the remaining amount of the unreacted unsaturated carboxylic acid component contained in the acid-modified polypropylene resin and the number average particle diameter of the acid-modified polypropylene resin in the aqueous dispersion both Since it was within the preferred range defined in the invention, the extrusion laminate had excellent adhesion even at a line speed of 100 m / min or more, and also had resistance to content.
In the method for producing the anchor coat agent of Example 8, the aqueous dispersion of the acid-modified polypropylene resin is insufficient, and the number average particle diameter in the aqueous dispersion can not be made within the preferable range defined in the present invention. The anchor coating agent was somewhat inferior in performance.
In Examples 12 to 16, it was confirmed that the delamination of the crease portion of the packaging material can be suppressed by using various additives in combination.

  On the other hand, in Comparative Examples 1 to 16, since the anchor coating agent is not a component specified in the present invention for the polypropylene component of the acid-modified polypropylene resin, adhesion is insufficient even when used for extrusion lamination of polypropylene resin There was a problem with PP odor.

In addition, the content resistance test of a present Example used salad oil for the content. Since salad oil has the property of causing a reduction in laminate strength more easily than snack foods, it can be judged that it has sufficient performance as a snack food package if good results can be obtained in this test using salad oil.
In addition, the packaging material obtained in the examples had a suppressed PP odor and was suitable for packaging of potato snacks. Although the mechanism by which the PP odor of the packaging material is suppressed in the present invention is unknown, the acid-modified polypropylene resin of the anchor coating agent used has a high degree of crystallinity and a high melting point. It is possible that the decomposition of the polypropylene resin is suppressed. Also, the relationship between the extrusion laminating line speed and the PP odor was obtained.

Claims (9)

An aqueous dispersion containing an acid-modified polypropylene resin and the aqueous medium, the polypropylene component of the acid-modified polypropylene resin, Ri Do isotactic structure, the direction of the methyl groups as side chains relative to the polypropylene backbone mismatch which is a ratio of the mismatch, an anchor coating agent for a polypropylene resin extrusion lamination, which is a 3.0 mol% der Ru homopolypropylene following methyl group in 100 mol% is the side chain of the polypropylene resin.   The anchor coating agent for polypropylene resin extrusion lamination according to claim 1, wherein the acid-modified polypropylene resin is an isotactic polypropylene- (anhydride) maleic acid binary copolymer.   The anchor coating agent for polypropylene resin extrusion lamination according to claim 1 or 2, wherein the remaining amount of unreacted unsaturated carboxylic acid component contained in the acid-modified polypropylene resin is 50 to 10,000 ppm.   The material according to any one of claims 1 to 3, wherein 1 to 100 parts by mass of at least one resin selected from polyethylene resin, polyurethane resin, and polyester resin is contained with respect to 100 parts by mass of acid-modified polypropylene resin. Anchor coating agent for polypropylene resin extrusion lamination.   It is a packaging material by which a thermoplastic resin film layer, an anchor coat layer, and an extrusion polypropylene resin layer are laminated in this order at least, and an anchor coat layer is for polypropylene resin extrusion lamination according to any one of claims 1 to 4. A packaging material characterized in that it is a coating film formed of an anchor coating agent.   The packaging material according to claim 5, wherein the packaging material is a snack food packaging material.   The packaging material according to claim 6, wherein the packaging material for snacks is a packaging material for potato snacks.   The anchor coat agent for polypropylene resin extrusion lamination according to any one of claims 1 to 4 is applied to at least one surface of a thermoplastic resin film layer and dried to form an anchor coat layer, and then the anchor is formed. A method for producing a packaging material, which comprises laminating molten polypropylene resin by extrusion lamination on a coat layer.   9. The method for producing a packaging material according to claim 8, wherein a line speed at which the polypropylene resin is laminated by extrusion lamination is 100 to 600 m / min.