JP7000872B2 - High drop bag strength laminate, packaging material using the laminate, packaging bag - Google Patents

Description

The present invention relates to a high-drop bag strength laminate for a packaging bag, a packaging material using the laminate, and a packaging bag.

Conventionally, in a laminate in which a sealant layer is laminated by an extruded laminate, the sealant layer is likely to peel off because the adhesive strength of the sealant layer is weak, and a packaging bag produced using the laminate has sufficient bag-dropping strength. If you do not fill the packaging bag with the contents and drop it, the packaging bag will be damaged, or if you tear the bag by hand when opening the packaging bag, the sealant layer will be on the tear end. There is a problem that the sealant layer is stretched and broken due to peeling, the tear line is disturbed, and the tearability, that is, the hand-cutting property is not good.

In reference to Patent Documents 1 to 3, an aqueous dispersion in which a polyolefin copolymer resin containing 0.01 to 5% by mass of unsaturated carboxylic acid or an anhydride thereof is dispersed so that the average particle size thereof is as small as 1 μm or less is dispersed. A laminate having a coating film of an aqueous dispersion which is a liquid and is formed so that the aqueous dispersion does not contain a non-volatile aqueous dispersion aid has excellent adhesiveness and hand-cutting openability. Are listed.
However, the drop impact resistance (high drop bag strength) of the stacks described in these was not sufficient.

Japanese Patent No. 369935 Japanese Patent No. 5029007 Japanese Patent No. 5415670

The present invention has been made to solve the above-mentioned problems, and the problems thereof are a laminated body for a packaging bag having a high drop bag strength, a packaging material using the laminated body, and a packaging bag. Is to provide.
High drop bag strength refers to the fact that the packaging bag is not easily damaged when the packaging bag filled with the contents is dropped, and the drop impact resistance.
In addition, it is easy to cut when opening the packaging bag, and the amount of organic solvent discharged when manufacturing the laminate can be reduced, which is excellent in performance and usability, and has little adverse effect on the environment. The subject is to provide packaging bags.

As a result of various studies, the present inventors have found a laminate having a specific layer structure made of a specific material and subjected to a specific aging treatment, and a packaging material and a packaging bag using the laminate. It was found that the problem could be solved.

The present invention is characterized by the following points.
1. 1. At least a base material layer (A), a dry lamination adhesive layer (C), a metal element-containing barrier layer (D), an anchor coat layer (E), a polyolefin-based adhesive layer (F), and a sealant layer. A high-drop strength laminate containing (G) and
The polyolefin-based adhesive layer (F) is adjacent to the sealant layer (G).
The anchor coat layer (E) is adjacent to the polyolefin-based adhesive layer (F).
The sealant layer (G) is a layer formed by laminating films or sheets by extrusion lamination via a melt-extruded polyolefin-based adhesive layer (F), and the high-drop bag strength laminate is completed. Later, a high-drop bag strength laminate that has been aged for 2 to 7 days in an environment of 35 ° C. or higher and 80 ° C. or lower.
2. 2. Further, the high drop bag strength laminate according to 1 above, which includes the reinforcing layer (B).
3. 3. The anchor coat layer (E) is a layer formed from an aqueous dispersion liquid in which a polyolefin resin is dispersed.
The aqueous dispersion is substantially free of the non-volatile aqueous aid.
The number average particle size of the polyolefin resin in the aqueous dispersion is 1 μm or less.
The high drop bag strength laminate according to 1 or 2 above.

4. The high-drop strength laminate according to 3 above, wherein the polyolefin-based resin is an unsaturated carboxylic acid-modified polyolefin-based resin.
5. The unsaturated carboxylic acid-modified polyolefin resin has a structure derived from the unsaturated carboxylic acid or the unsaturated carboxylic acid anhydride in 0.01% by mass or more and 5% by mass in the completely unsaturated carboxylic acid-modified polyolefin resin. The high drop bag strength laminate according to 4 above, which contains the following proportions.
6. The high drop bag strength laminate according to any one of 1 to 5 above, wherein the thickness of the anchor coat layer (E) is 0.05 g / m ² or more and 2 g / m ² or less.
7. 1. High drop bag strength laminate.
8. The polyolefin-based adhesive layer (F) contains LDPE or LLDPE and contains
The high drop bag strength laminate according to any one of 1 to 7 above, wherein the sealant layer (G) contains LDPE or LLDPE.
9. A high-drop bag strength packaging material comprising the high-drop bag strength laminate according to any one of 1 to 8 above.
10. A high-drop strength packaging bag made from the high-drop strength packaging material according to 9 above.

According to the present invention, it is possible to obtain a high-strength laminated body for a packaging bag, a packaging material using the laminated body, and a packaging bag.
In addition, it has good hand-cutting property when opening the packaging bag, and it is possible to reduce the amount of organic solvent discharged when manufacturing the laminate, which is excellent in performance and usability, and is environmentally friendly. It is possible to obtain a laminate, a packaging material, and a packaging bag with less adverse effects.

It is sectional drawing which shows an example of the laminated body which concerns on this invention. It is an external view which shows an example of the packaging bag which concerns on this invention.

<Laminated body>
The high drop bag strength laminate of the present invention has at least a base material layer (A), a dry lamination adhesive layer (C), a metal element-containing barrier layer (D), an anchor coat layer (E), and a polyolefin. It includes a resin adhesive layer (F) and a sealant layer (G). Further, if necessary, the reinforcing layer (B) may be included.
Here, it is preferable that the anchor coat layer (E), the polyolefin resin adhesive layer (F), and the sealant layer (G) are adjacent to each other.

The high-drop strength laminate of the present invention is preferably subjected to an aging treatment after the completion of the lamination.
If necessary, the high-drop strength laminate of the present invention may contain layers of the same type or different types as those described above, as long as they do not interfere with the stacking order.
Each layer included in the high drop bag strength laminate of the present invention, the stacking order of each layer, and the like will be described below.

[Base material layer (A)]
As the base material layer (A), a resin film or sheet generally used as a packaging material for packaging bags, synthetic paper, a film or sheet such as a paper base material can be used, and tensile strength, bending strength, etc. Those having excellent mechanical strength such as impact strength and excellent printability are preferable.
The base material layer (A) may be one layer or may be composed of two or more layers. In the case of two or more layers, it may be a layer having the same composition or a layer having a different composition.
Further, it is preferably a uniaxially or biaxially stretched resin film or sheet.

Specific resins include polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate; polyamide resins such as nylon 6, nylon 66, and MXD6 (polymethoxylylen adipamide); Examples thereof include cellophane; polyethylene-based resin, polypropylene-based resin, polyolefin-based resin of acid-modified polyolefin-based resin; polystyrene-based resin; polyurethane-based resin; acetal-based resin; EVOH and the like.

A suitable material can be freely selected and used according to the type of contents to be packaged and the usage conditions such as the presence or absence of heat treatment after filling, but among the above, polyester-based resin and polyamide-based resin are preferable. ..
In particular, a uniaxially stretched polyethylene terephthalate film or sheet, a biaxially stretched polypropylene film or sheet, or the like is suitable.

The resin film or sheet used for the base material layer (A) has workability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidant property, slipperiness, releasability, and flame retardancy, if necessary. , Antifungal properties, electrical properties, strength, etc. for the purpose of improving and modifying lubricants, cross-linking agents, antioxidants, UV absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, etc. A plastic compounding agent, an additive, or the like can be added, and the amount thereof can be arbitrarily added as long as it does not adversely affect other performance.

Specific paper base materials include, for example, strong-sized bleached or unbleached paper base materials, pure white roll paper, kraft paper, paperboard, coated paper, cast-coated paper, processed paper, high-quality paper, and the like. Can be used.

The resin film or sheet used for the base material layer (A) may be vapor-deposited with a metal or a metal oxide.
In addition, the film or sheet constituting the base material layer (A) and the base material layer (A) is previously subjected to corona discharge treatment, ozone treatment, oxygen gas, nitrogen gas, etc. before laminating in order to improve adhesion. It may be subjected to physical treatment such as low temperature plasma treatment and glow discharge treatment using the above, and chemical treatment such as oxidation treatment using chemicals.

The thickness of the base material layer (A) is preferably 10 μm or more and 50 μm or less, and more preferably 15 μm or more and 40 μm or less.
If it is thinner than the above range, the rigidity of the laminated body is too low and it tends to be difficult to exhibit high bag strength. If it is thicker than the above range, the rigidity of the laminated body becomes too high and the laminated body is processed. It tends to be difficult and the filling property of the contents tends to deteriorate.

[Reinforcing layer (B)]
The reinforcing layer (B) is a layer included in the laminated body as needed, and is a layer responsible for reinforcement such as tensile strength, bending strength, impact strength, piercing strength, breaking strength, toughness, and rigidity. By including the reinforcing layer (B), it is possible to expand the options for the configuration of other layers such as the base material layer (A) and the sealant layer (G).
As the reinforcing layer (B), the same known or commercially available resin uniaxial or biaxially stretched film or sheet as the substrate layer (A) can be used, depending on the type of contents to be packaged and the conditions of use. , You can freely select and use the suitable one.
Among the above, polybutylene terephthalate and uniaxial or biaxially stretched films or sheets of polyamide-based resins, particularly nylon-based resins are suitable.

The reinforcing layer (B) may be one layer or may be composed of two or more layers. In the case of two or more layers, it may be a layer having the same composition or a layer having a different composition.
Further, similarly to the base material layer (A), a metal or a metal oxide may be vapor-deposited, or a pretreatment for improving the adhesion may be performed.

[Dry lamination adhesive layer (C)]
The dry lamination adhesive layer (C) is a layer that imparts interlayer adhesiveness in the laminated body.
The dry lamination adhesive layer (C) can be formed by using a known or commercially available dry lamination (DL) adhesive.
Specific examples of the dry lamination adhesive include a two-component curable polyurethane adhesive, a two-component curable polyester adhesive, and a polyolefin-based (low-density polyethylene, ethylene-methacrylic acid copolymer, ethylene-acrylic acid copolymer). , Unsaturated carboxylic acid-modified polyolefin, ionomer, etc.), heat-adhesive resin and the like.

Since the dry lamination adhesive layer (C) is formed by dry lamination, it is possible to prevent deterioration of the adhesiveness due to the generation of pinhole voids in the dry lamination adhesive layer (C). In addition, the amount of organic solvent discharged during the production of the laminate can be reduced, and the adverse effect on the environment can be reduced.
The dry lamination adhesive layer (C) may be one layer or may be composed of two or more layers. In the case of two or more layers, it may be a layer having the same composition or a layer having a different composition.
Further, the dry lamination adhesive layers (C) having the same composition or different compositions may be laminated at two or more places in the laminated body.

[Metal element-containing barrier layer (D)]
The metal element-containing barrier layer (D) is a layer having a barrier property, and a metal foil or a vapor-deposited film made of an inorganic substance or an inorganic oxide containing a metal element can be used, and an aluminum foil, an aluminum vapor-deposited film, or an oxidation film can be used. One or more selected from the group consisting of an aluminum vapor-deposited film and a silicon oxide vapor-deposited film is preferable, and an aluminum foil or an aluminum-deposited film is particularly preferable.

Further, the metal element-containing barrier layer (D) may be composed of one layer or two or more layers. When composed of two or more layers, each layer may have the same composition, may have a different composition, or may not be laminated adjacent to each other.
Here, the barrier property refers to the permeation blocking property, the gas barrier property, the light blocking property, etc. of the contents to the outside, and is selected as necessary.
The storage stability of the contents can be enhanced by the permeation blocking property of the contents to the outside.

Specific examples of the gas barrier property include oxygen barrier property and water vapor barrier property. Oxygen and water vapor infiltrate into the packaging bag from the outside to deteriorate the contents, and moisture inside the packaging bag moves to the outside of the packaging bag. It is possible to prevent it from being dissipated, and it is possible to improve the storage stability of the contents.
Specific examples of the light-shielding property include visible light light-shielding property, ultraviolet light-shielding property, and the like, deterioration of the content due to light can be prevented, and the storage stability of the content can be improved.

The thickness of the metal element-containing barrier layer (D) is preferably 15 nm to 20 μm. In the case of a metal foil, 5 μm to 20 μm is preferable, and 1 nm to 20 μm is more preferable. In the case of a thin-film deposition film, 15 to 200 nm is preferable, and the more preferable thickness varies depending on the vapor-deposited species, but in the case of an aluminum-deposited film, 1 to 100 nm is more preferable, 15 to 60 nm is more preferable, and 10 to 40 nm is particularly preferable. .. In the case of a silicon oxide-deposited film or an aluminum oxide-deposited film, 1 to 100 nm is more preferable, 10 to 50 nm is further preferable, and 20 to 30 nm is particularly preferable.

When the metal element-containing barrier layer (D) is a metal foil, the metal element-containing barrier layer (D) adheres to another layer via the dry lamination adhesive layer (C) and the anchor coat layer (E). Can be done.
When the metal element-containing barrier layer (D) is a thin-film vapor deposition film, the metal element-containing barrier layer (D) can be formed by a conventionally known method using a conventionally known inorganic substance or an inorganic oxide. The composition and the forming method are not particularly limited.

Examples of the forming method include a physical vapor deposition method (Physical Vapor Deposition method, PVD method) such as a vacuum vapor deposition method, a sputtering method, and an ion plating method, or a plasma chemical vapor deposition method, a thermochemical vapor deposition method, and the like. And a chemical vapor deposition method (Chemical Vapor Deposition method, CVD method) such as a photochemical vapor deposition method can be mentioned.

When forming the vapor deposition film, the surface to be vaporized can be pretreated as needed. Specifically, corona discharge treatment, ozone treatment, low temperature plasma treatment using oxygen gas or nitrogen gas, glow, etc. Physical treatment such as electric discharge treatment or chemical treatment such as oxidation treatment using chemicals may be performed.

When the metal element-containing barrier layer (D) is a vapor-filmed film, it may be formed on a film or sheet constituting the base material layer (A) or the reinforcing layer (B), or may be biaxially stretched. It may be formed on a film or sheet made of polyethylene terephthalate, polyacrylonitrile, or an ethylene-vinyl alcohol copolymer.

[Anchor coat layer (E)]
The anchor coat layer (E) is a layer that imparts interlayer adhesiveness in the laminated body, and is preferably laminated adjacent to the polyolefin-based adhesive layer (F).
It is also possible to use an adhesive having the same composition as the anchor coat layer (E) for a layer that is not adjacent to the polyolefin-based adhesive layer (F), but in that case, it is not the anchor coat layer (E) and is usually used. It is classified into the anchor coat layer of.
By having the above structure, good adhesiveness is obtained in the laminated body.

The thickness of the anchor coat layer (E) is preferably 0.05 g / m ² or more and 2 g / m ² or less. If it is thinner than the above range, the anchor coat layer (E) tends to be inhomogeneous, and if it is thicker than the above range, pinhole voids and the like are likely to occur in the anchor coat layer (E), and the adhesiveness is lowered. It will be easier.
The components of the anchor coat layer (E) are not particularly limited, and a commonly used urethane-based, polyester-based, isocyanate-based, or polyolefin-based anchor coating agent is used to obtain a gravure coating method, a reverse roll coating method, and the like. It can be formed by applying, drying or the like by a known method such as a knife coating method or a kiss coating method. Among the above, the anchor coat layer (E) is preferably a layer formed from an aqueous dispersion liquid in which a polyolefin resin is dispersed.

When the anchor coat layer (E) is formed from an aqueous dispersion in which a polyolefin resin is dispersed, for example, after applying the aqueous dispersion, it is dried at 80 to 120 ° C. or melt-extruded at 270 to 330 ° C. It can be formed by shaving.
By using the aqueous dispersion for the anchor coat layer (E), the interlayer adhesion strength is improved, the interlayer peeling is reduced, and the bag drop strength is improved as compared with the case where a normal urethane-based anchor coat agent or the like is used. Can be improved.
Further, the polyolefin-based resin is more preferably an unsaturated carboxylic acid-modified polyolefin-based resin.

The content of the polyolefin resin in the aqueous dispersion is preferably 1 to 60% by mass, more preferably 3 to 55% by mass, further preferably 5 to 50% by mass, and particularly preferably 10 to 45% by mass. By setting the content in the above range, good film forming property can be obtained.

Here, it is preferable that the aqueous dispersion does not substantially contain the non-volatile aqueous auxiliary. As a result, the plasticization of the anchor coat layer (E) can be prevented, and the adhesive strength at the interface of the anchor coat layer (E) can be increased.
"Substantially free of the non-volatile water-based auxiliary agent" means that the non-volatile water-based auxiliary agent is not positively added to the system, and as a result, these are not contained. It is particularly preferable that the content of such a non-volatile aqueous aid is zero, but it is contained, for example, less than 0.1% by mass with respect to the polyolefin resin component as long as the effect of the present invention is not impaired. There is no problem.

The main solvent of the aqueous dispersion is water, but water-soluble alcohols, ethers and the like may be contained, and even if a small amount of organic solvent component added as a plasticizer or the like is contained in the resin component. good.

Further, a volatile aqueous aid may be contained in a small amount, and for example, an unsaturated carboxylic acid-modified polyolefin-based resin dispersed by containing a basic compound such as ammonia or a volatile organic amine compound. Stability can be imparted by preventing the aggregation of fine particles.

Further, by using the aqueous dispersion, the amount of harmful organic solvent discharged during the production of the laminate can be reduced, so that the adverse effect on the environment can be reduced.
Further, the polyolefin-based resin is dispersed in the aqueous dispersion in the state of fine particles, and the number average particle diameter of the fine particles is preferably 1 μm or less, preferably 0.01 μm or more and 1 μm or less. More preferred. Further, the weight average particle diameter is preferably 1 μm or less, more preferably 0.01 μm or more and 1 μm or less. If it is smaller than the above range, it becomes difficult to prepare an aqueous dispersion and the cost tends to increase because the process is complicated. If it is larger than the above range, the anchor coat layer (E) is not suitable. It tends to be homogeneous and may reduce the adhesiveness.

(Polyolefin resin)
The polyolefin-based resin is a homopolymer or a copolymer using one kind or two or more kinds of α-olefins as a raw material monomer.
Specific examples of the α-olefin include α-olefins having 2 to 8 carbon atoms, preferably 2 to 6 carbon atoms such as ethylene, propylene, isobutylene and hexene. Preferred α-olefins are ethylene and propylene.

Further, the polyolefin may be a copolymer in which a monomer other than α-olefin is used in combination as the monomer. Examples of such other monomers include vinyl ester-based monomers such as vinyl acetate.

Specific examples of the polyolefin-based resin preferably used for the anchor coat layer (E) include linear low-density polyethylene (LLDPE), an ethylene-α / olefin copolymer polymerized using a single-site catalyst, and low-density polyethylene. (LDPE), polyethylene-based resin such as ionomer; polypropylene-based resin; polybutadiene-based resin, ethylene-methacrylic acid copolymer, ethylene-acrylic acid copolymer; unsaturated carboxylic acid-modified polyolefin-based resin, and the like.

The polystyrene-equivalent weight average molecular weight of the polyolefin resin in the present invention is preferably 5,000 to 200,000, more preferably 10,000 to 150,000, and 20,000 to 120,000. It is more preferably 30,000 to 100,000, and most preferably 35,000 to 80,000.
If the weight average molecular weight is less than the above range, the adhesiveness to the substrate tends to be lowered, and the obtained coating film tends to be hard and brittle. On the other hand, if the weight average molecular weight exceeds the above range, the resin It tends to be difficult to make it water-based.

(Unsaturated carboxylic acid-modified polyolefin resin)
The unsaturated carboxylic acid-modified polyolefin resin is a copolymer of an unsaturated carboxylic acid or a derivative thereof and an α-olefin, or a resin obtained by reacting a polyolefin with an unsaturated carboxylic acid or a derivative thereof, and is a polyolefin-based resin. It is a resin having a form in which an unsaturated carboxylic acid is incorporated in the main chain or the side chain of the resin and a chemical bond is formed between the polyolefin-based resin and the unsaturated carboxylic acid.

The form of copolymerization is not limited, and examples thereof include random copolymerization, block copolymerization, and graft copolymerization. Further, it may be a binary copolymerization or a copolymerization of three or more elements.

The unsaturated carboxylic acid is a compound having one or two or more unsaturated bonds and one or two or more carboxyl groups in one molecule.
Specific examples of unsaturated carboxylic acids include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, etacrilic acid and crotonic acid; unsaturated dicarboxylic acids such as itaconic acid, maleic acid and fumaric acid; and derivatives thereof. Can be mentioned.
Examples of the derivative of the unsaturated carboxylic acid include chlorides, amides, esters and anhydrides of the above-mentioned acids, and in the case of unsaturated dicarboxylic acids, half derivatives such as half esters and half amides can also be mentioned.
Examples of the acid ester include methyl ester, ethyl ester, propyl ester, dimethylaminoethyl ester and the like.

The unsaturated carboxylic acid-modified polyolefin resin has a structure derived from an unsaturated carboxylic acid or an unsaturated carboxylic acid anhydride in 0.01% by mass or more and 5% by mass or less in a completely unsaturated carboxylic acid-modified polyolefin resin. It is preferable that it is contained in the ratio of. If it is less than the above range, it tends to be difficult to liquefy (liquefy) the resin, and it tends to be difficult to obtain a good aqueous dispersion. If it is more than the above range, the stability of the aqueous dispersion is lowered, and it tends to be difficult to adjust the number average particle size of the unsaturated carboxylic acid-modified polyolefin resin in the aqueous dispersion within the above range, and adhesion is likely to occur. There is a risk of reducing the sex.

(Non-volatile water-based aid)
In the present invention, the non-volatile aqueous auxiliary is a non-volatile agent or compound added for the purpose of promoting aqueous dispersion or stabilizing the aqueous dispersion in the production of the aqueous dispersion.
Here, the non-volatile means that it does not have a boiling point at normal pressure or has a high boiling point at normal pressure (for example, 300 ° C. or higher).

Examples of the non-volatile aqueous aid include compounds having a protective colloidal action such as emulsifiers and surfactants, modified waxes, acid-modified compounds having a high acid value, and water-soluble polymers.
Examples of the emulsifier include a cationic emulsifier, an anionic emulsifier, a nonionic emulsifier, and an amphoteric emulsifier, and in addition to those generally used for emulsion polymerization, surfactants are also included. For example, examples of the anionic emulsifier include sulfate ester salts of higher alcohols, higher alkyl sulfonates, higher carboxylates, alkylbenzene sulfonates, polyoxyethylene alkyl sulfate salts, polyoxyethylene alkyl phenyl ether sulfate salts, and vinyl sulfosuccinates. Examples of the nonionic emulsifier include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyethylene glycol fatty acid ester, ethylene oxide propylene oxide block copolymer, polyoxyethylene fatty acid amide, and ethylene oxide-propylene oxide. Examples thereof include compounds having a polyoxyethylene structure such as copolymers and sorbitan derivatives such as polyoxyethylene sorbitan fatty acid ester, and examples of the amphoteric emulsifier include laurylbetaine and lauryldimethylamine oxide.

Compounds having a protective colloidal action such as surfactants, modified waxes, acid-modified compounds having a high acid value, and as water-soluble polymers, polyvinyl alcohol, carboxyl group-modified polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, Acid-modified polyolefin waxes having a number average molecular weight of 5000 or less, such as modified starch, polyvinylpyrrolidone, polyacrylic acid and salts thereof, carboxyl group-containing polyethylene wax, carboxyl group-containing polypropylene wax, and carboxyl group-containing polyethylene-propylene wax, and their respective Salt, acrylic acid-maleic anhydride copolymer and its salts, styrene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid copolymer, isobutylene-maleic anhydride alternating polymer, (meth) A carboxyl group-containing polymer having an unsaturated carboxylic acid content of 10% by mass or more, such as an acrylic acid- (meth) acrylic acid ester copolymer and a salt thereof, polyitaconic acid and a salt thereof, and a water-soluble acrylic common weight having an amino group. Examples thereof include compounds generally used as dispersion stabilizers for fine particles, such as coalescing, gelatin, gum arabic, and casein.

[Polyolefin-based adhesive layer (F)]
The polyolefin-based adhesive layer (F) is a layer adjacent to the sealant layer (G) and the anchor coat layer (E), and is a layer that plays a role of adhering the sealant layer (G) into the laminated body, and is a polyolefin-based adhesive layer. It is a layer containing a resin.
Specific examples of the polyolefin-based resin used for the polyolefin-based adhesive layer (F) include linear low-density polyethylene (LLDPE), an ethylene-α / olefin copolymer polymerized using a single-site catalyst, and low density. Examples thereof include polyethylene-based resins such as polyethylene (LDPE) and ionomer; polypropylene-based resins; polybutadiene-based resins; ethylene-methacrylic acid copolymers, unsaturated carboxylic acid-modified polyolefin-based resins such as ethylene-acrylic acid copolymers, and the like. ..

The polyolefin-based adhesive layer (F) can contain one or more of the above resins, and if necessary, a known bending resistance improving agent, an inorganic or organic additive, or the like is blended. can do.
Among the above, the polyolefin-based adhesive layer (F) preferably contains linear low-density polyethylene (LLDPE) or low-density polyethylene (LDPE), and includes linear low-density polyethylene (LLDPE). Is particularly suitable.
The polyolefin-based adhesive layer (F) is formed by extruding a resin composition containing a polyolefin-based resin onto the anchor coat layer (E) or extruding a lanate (so-called sandwich laminate) together with the sealant layer (G). Can be formed.

The thickness of the polyolefin-based adhesive layer (F) is preferably 5 μm or more and 30 μm or less, and more preferably 10 μm or more and 20 μm or less. If it is thinner than the above range, it tends to be difficult to sufficiently exhibit the adhesive effect, and if it is thicker than the above range, it may affect the rigidity of the entire laminate, which is not preferable.

[Sealant layer (G)]
The sealant layer (G) is a layer that imparts functions such as heat sealability, bending resistance, and impact resistance to the laminated body, and is adjacent to the polyolefin-based adhesive layer (F) in the laminated body. It is a layer laminated on the outermost layer of the laminated body.
The sealant layer (G) may be one layer or may be composed of two or more layers. In the case of two or more layers, it may be a layer having the same composition or a layer having a different composition. However, the layer constituting the surface layer of the laminated body preferably contains a resin having excellent heat-sealing properties.

Specific resins include, for example, polyethylene, low density polyethylene, medium density polyethylene, high density polyethylene, linear (linear) low density polyethylene, metallocene polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ionomer resin, and the like. Ethylene- (meth) ethyl acrylate copolymer, ethylene- (meth) acrylate copolymer, ethylene-propylene copolymer, methylpentene polymer, polyethylene or polypropylene and other polyolefin resins are made into acrylic acid, methacrylic acid, and anhydrous. Polyethylene resin modified with unsaturated carboxylic acid such as maleic acid, fumaric acid and others, ternary copolymer resin of ethylene- (meth) acrylic acid ester-unsaturated carboxylic acid, cyclic polyolefin resin, cyclic olefin copolymer, polyethylene terephthalate. (PET), polyacrylonitrile (PAN) and the like.
As the sealant layer (G), a resin film or sheet using one or more of the above resins, a resin coating film, or the like can be used.
If necessary, a known bending resistance improving agent, an inorganic or organic additive, or the like can be added to the above resin.

As the film or sheet forming the resin layer, any unstretched film or sheet, or a stretched film or sheet stretched in the uniaxial or biaxial direction can be used.
Among the above, the sealant layer (G) preferably contains a polyolefin-based resin from the viewpoint of heat-sealing property, and particularly preferably contains low-density polyethylene (LDPE) or linear low-density polyethylene (LLDPE). In particular, it is preferable to include LLDPE.

As a method of laminating the sealant layer (G), the sealant layer (G) is used together with a resin composition containing a polyolefin resin for the extruded polyolefin-based adhesive layer (F) on the anchor coat layer (E). A method of extruding and laminating the resin film or sheet of the above (so-called sandwich laminating), or extruding a resin composition containing a polyolefin resin for the polyolefin adhesive layer (F) onto the anchor coat layer (E). Further, a method of extruding the resin composition for the sealant layer (G) and co-extruding lanate (so-called sandwich laminating) on the resin composition, or further, or a polyolefin-based adhesive previously formed on the anchor coat layer (E). Examples thereof include a method of heat-pressing a resin film or a sheet for the sealant layer (G) on the agent layer (F).

In the above, the resin composition for the sealant layer (G) is extruded together with the resin composition containing the polyolefin-based resin for the polyolefin-based adhesive layer (F) melt-extruded onto the anchor coat layer (E). The method of laminating is preferable, and the method of heat-bonding the resin film or sheet for the sealant layer (G) is more preferable.
As described above, the sealant layer (G) is firmly heat-bonded to the surface of the anchor coat layer (E) via the polyolefin-based adhesive layer (F).

The thickness of the sealant layer (G) is preferably 5 to 500 μm, more preferably 10 to 250 μm, and even more preferably 15 to 100 μm. If it is thinner than the above range, it tends to be difficult to obtain sufficient heat seal strength, and if it is thicker than the above range, the cost tends to increase and the film tends to become hard and workability tends to deteriorate.

<Aging process>
The high drop bag strength laminate of the present invention is a product that has been subjected to an aging treatment after the completion of the lamination.
By the aging treatment, the laminating strength at the interface of each layer in the high drop strength laminate is improved even at the interface of the layers laminated by the extruded laminating, and in particular, the anchor coat layer (E) interface and the polyolefin resin adhesive layer are improved. The laminating strength of the interface between the (F) and the sealant layer (G) is improved, and the packaging bag can sufficiently withstand even a heavy content.

Further, by improving the laminating strength, the falling strength (drop impact resistance) of the packing bag filling is improved.
Further, this makes it possible to prevent the sealant layer (G) from peeling off at the time of opening the hand-cut and the opening property of the hand-cut.
As a method of the aging treatment, for example, a method of storing the produced laminated body in a roll-wound state in a storage kept at a constant temperature can be mentioned.

The aging temperature is preferably 35 ° C. or higher and 80 ° C. or lower. When the temperature is lower than the above range, the effect of the aging treatment tends to be difficult to be fully exhibited, and when the temperature is higher than the above range, various changes due to the aging treatment tend to proceed rapidly. There is a possibility that bleed-out of the agent or the like, loosening of the sealant layer (G), blocking or the like may occur in the wound laminate, control tends to be complicated, and productivity tends to be inferior.

The aging time is preferably 2 to 7 days. If it is shorter than the above range, the effect of the aging treatment tends to be difficult to be fully expressed, and if it is longer than the above range, the effect of the aging treatment does not change so much even though it takes a long time, and the productivity tends to be inferior. Easy to become.

<Packaging material>
The high-drop bag strength packaging material of the present invention comprises the above-mentioned high-drop bag strength laminate.

<Packaging bag>
The high-drop bag strength packaging bag of the present invention can be manufactured by heat-sealing the above-mentioned high-drop bag strength packaging material into a bag shape.
The aspect of the packaging bag according to the present invention is not particularly limited, and for example, a flat bag such as a three-way seal type bag or a four-way seal type bag, a pillow type bag, a self-standing bag such as a standing pouch, or a gusset bag. Alternatively, it may be a packaging bag of any aspect such as these application forms.

The raw materials used in the examples are as follows.
PET film 1: Biaxially stretched PET film manufactured by Toyobo Co., Ltd., T-4102. Single-sided corona treatment. 12 μm thick.
PBT film 1: Biaxially stretched PBT film manufactured by Kohjin Film & Chemicals Co., Ltd., Boblet ST. Single-sided corona treatment. 15 μm thick.
Nylon film 1: Biaxially stretched nylon film manufactured by Toyobo Co., Ltd., Harden film N1200. Double-sided corona treatment. Thickness 15 μm.
Nylon film 2: Biaxially stretched nylon film manufactured by Toyobo Co., Ltd., Harden film N7476. 15 μm thickness. Single-sided aluminum vapor deposition.
LLDPE1: Linear low-density polyethylene manufactured by Prime Polymer Co., Ltd., SP1071C. MFR 10g / 10 minutes.
LLDPE film 1: Mitsui Chemicals Tohcello Co., Ltd. T.I. U. X-HC. 100 μm thick.
Aluminum foil 1: Toyo Aluminum Co., Ltd. 1N30.7 μm thick.
DL Adhesive 1: Two-component curable polyurethane adhesive manufactured by Toyo Morton Co., Ltd., TM-570 / CAT-RT37 = weight ratio 18/1.
Anchor coating agent 1: Arrow base manufactured by Unitika Ltd. An aqueous dispersion of unsaturated carboxylic acid-modified polyolefin resin.
Anchor coating agent 2: A-3210 / A-3075 manufactured by Mitsui Chemicals, Inc. Urethane type.

[Example 1]
The PET film 1 as the base material layer (A) and the nylon film 1 as the reinforcing layer (B) are laminated by dry lamination via the DL adhesive 1 as the dry lamination adhesive layer (C). Further, one surface of the nylon film and the aluminum foil 1 as the metal element-containing barrier layer (D) were laminated by dry lamination via the DL adhesive 1. Then, the anchor coating agent 1 as the anchor coating layer (E) was applied to one surface of the aluminum foil in an amount such that the weight after drying was 0.5 g / m ² , and dried to obtain a laminate A.

Layer structure of laminate A: PET film 1 (12 μm) / DL adhesive 1 (3 μm) / nylon film 1 (15 μm) / DL adhesive 1 (3 μm) / aluminum foil 1 (7 μm) / anchor coating agent 1 (0) .5g / m ² )
Next, LLDPE1 as a polyolefin-based adhesive layer (F) is melt-extruded onto one surface of the anchor coating agent of the laminate A, and LLDPE film 1 as a sealant layer (G) is further laminated on LLDPE1 for extrusion lamination. Obtained a laminated body B.
Then, the laminated body B was subjected to an aging treatment at 35 ° C. for 8 days to obtain a laminated body.

Layer structure of laminate: PET film 1 (12 μm) / DL adhesive 1 (3 μm) / nylon film 1 (15 μm) / DL adhesive 1 (3 μm) / aluminum foil 1 (7 μm) / anchor coating agent 1 (0. 5 g / m ² ) / LLDPE 1 (15 μm) / LLDPE film 1 (100 μm)
Various evaluations were carried out using the obtained laminate. The results are shown in Table 1.

[Example 2]
The aging treatment conditions were changed to 40 ° C. for 3 days, and the same operation as in Example 1 was carried out to obtain a laminate, which was evaluated in the same manner. The results are shown in Table 1.

[Example 3]
The operation was carried out in the same manner as in Example 1 except that the aging treatment conditions were changed to 80 ° C. for 2 days to obtain a laminate, which was evaluated in the same manner. The results are shown in Table 1.

[Example 4]
The operation was carried out in the same manner as in Example 2 except that the anchor coating agent 1 was changed to the anchor coating agent 2, and a laminated body was obtained and evaluated in the same manner. The results are shown in Table 1.

[Example 5]
The operation was carried out in the same manner as in Example 2 except that the nylon film 1 and the aluminum foil 1 were changed to the aluminum vapor-deposited film-containing nylon film 2, and a laminate was obtained and evaluated in the same manner. The results are shown in Table 1.

[Examples 6 and 7]
The operation was carried out in the same manner as in Example 2 except that the thickness of the anchor coat layer (E) was changed to the thickness shown in Table 1, and a laminated body was obtained and evaluated in the same manner. The results are shown in Table 1.

[Example 8]
The PET film 1 as the base material layer (A) was changed to the PBT film 1, and the reinforcing layer (B) and the dry lamination adhesive layer (C) for laminating the reinforcing layer (B) were not provided. Except for the above, the same operation as in Example 2 was carried out to obtain a laminated body, which was evaluated in the same manner. The results are shown in Table 1.

[Comparative Example 1]
A laminate was obtained by the same operation as in Example 1 except that the aging treatment was not performed, and the same evaluation was performed. The results are shown in Table 1.

[Comparative Example 2]
A laminate was obtained by the same operation as in Example 2 except that the aging treatment was not performed, and the same evaluation was performed. The results are shown in Table 1.

<Evaluation method>
[Laminate strength]
A strip-shaped test piece having a width of 15 mm was cut out from the laminate, and approximately 10 mm at the end short side of the test piece was peeled off with an adhesive layer adjacent to the sealant layer (G) sandwiched between them. Using RTC-1310A manufactured by Orientec, the maximum load when peeled by the T-shaped peeling method (tensile speed 50 mm / min) under an atmosphere of 25 ° C. was measured and used as the laminate strength (N / 15 mm width). Furthermore, the peeling interface site was confirmed. The notations in Table 1 have the following meanings. Lamination strength of 3N / 15 mm or more was accepted.
In the table, "impossible to peel" indicates that the laminate strength was too strong to be peeled, and "existing peel" indicates that the laminate had already been peeled before the peel test.

[Drop impact resistance]
Using the laminate, the gusset bag shown in FIG. 2 was prepared with the following dimensions, filled with 500 ml of water, degassed and sealed, and sealed to prepare a test piece.
Then, after storing at 3 ° C. for 24 hours, the test piece was dropped 10 times from a height of 1.2 m in a horizontal orientation, and then dropped 10 times in a vertically standing orientation to check for water leakage. Detected a defect.
Overall width of the bag: 135mm
Overall length of bag: 225 mm
Folded length of bottom gusset 14: 37 mm
Width of the maximum part of the spout part seal part 17: 40 mm
Length of maximum part of spout part seal part 17: 55 mm
Overall width of the position where the half-cut line 21 is provided: 24 mm
Tapered angle of spout 20: Approximately 36 °
Method of manufacturing half-cut wire 21: Laser irradiation Half-cut wire spacing: 0.7 mm
Half-cut line depth: Approximately 30 μm

[Summary of evaluation results]
The laminated bodies of Examples 1 to 8 subjected to the aging treatment showed strong laminating strength, and the packaging bag made from the laminated body showed strong drop impact resistance.
However, the comparative example having the same layer structure but not subjected to the aging treatment showed inferior results.

1 High drop bag strength laminate 2 Base material layer (A)
3 Dry lamination adhesive layer (C)
4 Reinforcing layer (B)
5 Barrier layer containing metal element (D)
6 Anchor coat layer (E)
7 Polyolefin-based adhesive layer (F)
8 Sealant layer (G)
10 Gazette bag 11, 11'Wall surface film 12 Bottom film folded part 13a, 13b Bottom film notch part 14 Gusset part 15 Bottom seal part 16a, 16b Side seal part 17 Note outlet part Seal part 18 Top seal part 19a, 19b Cut Notch 20 Spout 21 Half-cut line 22 Notch

Claims (10)

At least a base material layer (A), a dry lamination adhesive layer (C), a metal element-containing barrier layer (D), an anchor coat layer (E), a polyolefin-based adhesive layer (F), and a sealant layer. A high-drop strength laminate containing (G) and
The base material layer (A), the dry lamination adhesive layer (C), the metal element-containing barrier layer (D), the anchor coat layer (E), the polyolefin-based adhesive layer (F), and the sealant layer (G) are in this order. It is laminated and
The polyolefin-based adhesive layer (F) is adjacent to the sealant layer (G).
The anchor coat layer (E) is a layer formed from an aqueous dispersion liquid in which a polyolefin resin is dispersed, and is adjacent to the polyolefin adhesive layer (F).
The polystyrene-equivalent weight average molecular weight of the polyolefin resin is 10,000 to 150,000.
The sealant layer (G) is a layer formed by laminating films or sheets by extrusion lamination via a melt-extruded polyolefin-based adhesive layer (F).
The high drop bag strength laminate is a high drop bag strength laminate that has been aged for 2 to 7 days in an environment of 35 ° C. or higher and 80 ° C. or lower after completion of the lamination. The high-drop strength laminate according to claim 1, further comprising a reinforcing layer (B). The anchor coat layer (E) is a layer formed from an aqueous dispersion liquid in which a polyolefin resin is dispersed.
The aqueous dispersion is substantially free of the non-volatile aqueous aid.
The high-drop strength laminate according to claim 1 or 2, wherein the number average particle size of the polyolefin-based resin in the aqueous dispersion is 1 μm or less. The high-drop strength laminate according to claim 3, wherein the polyolefin-based resin is an unsaturated carboxylic acid-modified polyolefin-based resin. The unsaturated carboxylic acid-modified polyolefin resin has a structure derived from the unsaturated carboxylic acid or the unsaturated carboxylic acid anhydride in 0.01% by mass or more and 5% by mass in the total unsaturated carboxylic acid-modified polyolefin resin. The high drop bag strength laminate according to claim 4, which comprises the following proportions. The high drop bag strength laminate according to any one of claims 1 to 5, wherein the thickness of the anchor coat layer (E) is 0.05 g / m ² or more and 2 g / m ² or less. Any one of claims 1 to 6, wherein the metal element-containing barrier layer (D) is one or more selected from the group consisting of an aluminum foil, an aluminum vapor-deposited film, an aluminum oxide vapor-deposited film, and a silicon oxide vapor-deposited film. The high drop bag strength laminate described in the section. The polyolefin-based adhesive layer (F) contains LDPE or LLDPE and contains
The sealant layer (G) comprises LDPE or LLDPE.
The high drop bag strength laminate according to any one of claims 1 to 7. A high-drop strength packaging material comprising the high-drop strength laminate according to any one of claims 1 to 8. A high-drop strength packaging bag made from the high-drop strength packaging material according to claim 9.

Images