JP5050833B2 - Laminated body - Google Patents

Description

  The present invention relates to a laminate, and more specifically, for excellent perfume retention and reducing environmental load, and further for resource saving, recycling society, prevention of global warming, activation of agriculture, etc. The present invention relates to a laminate using biomass resin.

  In the present specification, “ratio”, “part”, “%” and the like indicating the composition are based on mass unless otherwise specified, and the “/” mark indicates that they are integrally laminated. “Biomass” is “biological origin”, “biomass resin” is “biological resin”, “PE” is “polyethylene”, “LDPE” is “low density polyethylene”, “EMAA” is “ethylene-methacrylic acid” "Copolymer", "resin layer" is "heat seal layer", "HS layer", "sealant" or "sealant film", "PET" is "biaxially stretched polyethylene terephthalate", "ON" is "biaxially stretched" Polyamide "is an abbreviation, functional expression, common name, or industry term.

  (Main applications) Main applications of soft packaging bags such as pouches and stand pouches manufactured from the laminate of the present invention include beverages such as juices, soft drinks and alcohol, liquids such as ice creams, frozen desserts and yogurts. In addition, it is a container for liquid food containing viscous, solid content, etc., which reduces environmental burdens, and has also been advocated for resource saving, recycling society, prevention of global warming, and activation of agriculture. However, it has excellent fragrance retention, reduces the burden on the environment, and also requires resource saving, recycling society, prevention of global warming, activation of agriculture, etc., and heat seal equivalent to polyolefin resin There is no particular limitation as long as it is an application that also requires the property.

(Background Art) Soft packaging such as containers for liquid foods that are liquid, viscous, or solid, require water resistance, and a resin layer, usually polyethylene or wax, is laminated on the inner surface of the container. Since packaging materials are usually disposed of only once, the amount of garbage increases, and since it is hardly decomposed, it remains, and the burden on the environment is large. There are also problems such as the destruction of the living environment. Therefore, it is preferable to use a biomass material using biological resources. In the present specification, a resin derived from a living organism is particularly referred to as a biomass resin. If it is this biomass resin, even if it is incinerated after use, it will return to the organism through carbon dioxide, to the organism again through composting, etc., from the organism to the biomass resin, and to suppress the emission of carbon dioxide It is also effective in preventing global warming and revitalizing agriculture, and is also resource-saving because it does not use petroleum resources.
Therefore, as a laminate using biomass resin, it has excellent fragrance retention, reduces the burden on the environment, and even if it uses biomass resin approaching resource saving and recycling society, the layer containing the biomass resin is used. It has good suitability for film formation and can be made into a laminate, and in the production of pouches and standing pouches, it has the same heat sealability as polyolefin resin, and can be mass-produced easily and at low cost with conventional equipment. In addition, it is required to be able to be used for soft packaging such as liquid pouches and standing pouches.

(Prior Art) Conventionally, a biodegradable composite material using only polylactic acid or a derivative thereof is known as a biodegradable material that is one of biomass resins (see, for example, Patent Document 1). However, it is related to the biodegradable composite material itself, and the production of the biodegradable composite material is not suitable for mass production by applying a heat press and is also suitable for use as a packaging container. Such performance is not described or suggested.
Also, it contains a lactic acid resin (component (A)) and an ethylene / unsaturated carboxylic acid copolymer (component (B)) and / or an ionomer component (C) of an ethylene / unsaturated carboxylic acid copolymer). There is known a laminate comprising a layer comprising a lactic acid resin composition comprising (see, for example, Patent Document 2). However, this laminate has water vapor barrier properties, has the advantages of biodegradability and low combustion heat, has excellent impact strength, has excellent sealant performance such as low temperature heat sealability and hot tack properties, It is described that it can be suitably used as a wide range of materials such as various packaging materials such as food, electronics, chemicals, cosmetics, agricultural materials, civil engineering and construction materials, compost materials, etc. There is no suggestion.
Further, selected from the group consisting of biodegradable polymer (a), polymer (b), ionomer resin, oxazoline-based compatibilizer, elastomer-based compatibilizer, reactive compatibilizer, and copolymer-based compatibilizer. A biodegradable plastic material containing at least one compatibilizer (c) is known (for example, see Patent Document 3). However, there is no description or suggestion about aroma retention.

JP-A-4-334448 JP 2004-2773 A Japanese Patent Laid-Open No. 2005-248160

  In order to solve the above-described problems, the present inventors have made extensive studies and have completed the present invention. Its purpose is excellent in perfume retention, reducing environmental load, and even when using biomass resin approaching resource-saving and recycling society, the processability of the layer containing the biomass resin is good and it is laminated at higher speed. In addition, because it has excellent heat sealability in the manufacture of pouches and standing pouches, etc., it can be easily manufactured with conventional equipment and can be used for flexible packaging such as liquid pouches and standing pouches. Is to provide.

To solve the above problem,
The laminate according to claim 1 is a laminate having a base material and a resin layer containing a biomass resin and a synthetic resin on at least one side of the base material, wherein the biomass resin contains 50% by weight or more of a lactic acid component. A polylactic acid containing a copolymer of lactic acid and another aliphatic hydroxycarboxylic acid, a copolymer of lactic acid, an aliphatic polyhydric alcohol and an aliphatic polybasic acid, or a mixture of any of the above The synthetic resin is low density polyethylene, linear low density polyethylene, ethylene-unsaturated carboxylic acid copolymer, ethylene-unsaturated carboxylic acid ester copolymer, acid-modified polyolefin, ionomer, or a combination thereof. a certain polyolefin resin, the mixing ratio of the biomass resin and the synthetic resin of the resin layer is by weight 50 to 90: 50 Is 10, so excellent aroma retention is obtained by.
The laminate according to the invention of claim 2 is the laminate according to claim 1, wherein the biomass resin is a polylactic acid resin, the synthetic resin is a polyolefin resin, and Even if the orange juice is in contact with the resin layer , the fragrance and flavor are not impaired and the fragrance is excellent.

According to the present invention of claim 1, even when using a biomass resin that reduces environmental load and approaches a resource-saving and recycling society, the layer containing the biomass resin has good workability and is laminated at a higher speed. In addition, it has excellent heat sealability in the manufacture of pouches and standing pouches, can be easily manufactured with conventional equipment, and can also be used for soft packaging such as liquid pouches and standing pouches. A laminate having excellent properties is provided.
According to the second aspect of the present invention, in addition to the effect of the first aspect, it has the same heat sealability as that of the polyolefin-based resin, and even when the orange juice is in contact with it, the fragrance and the flavor are not easily lost, and it is further preserved. A laminate having excellent fragrance is provided.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view of a laminate showing one embodiment of the present invention.
FIG. 2 is a cross-sectional view of a laminate showing one embodiment of the present invention.
FIG. 3 is a cross-sectional view of a laminate showing one embodiment of the present invention.

  As shown in FIG. 1, the laminate 10 of the present invention has a resin layer 19 containing a biomass resin and a synthetic resin on at least one surface of a substrate 11. The biomass resin is a microorganism-producing polyester and / or an aliphatic polyester, and the mixing ratio of the biomass resin and the synthetic resin in the resin layer 19 is 50 to 90:50 to 10 on a mass basis. By doing in this way, heat sealability and aroma retention can be made compatible. In addition, since the resin layer 19 is made into a soft packaging body by heat sealing and is in contact with the contents, those skilled in the art also refer to an HS layer, a sealant, and a sealant film. Preferably, the biomass resin is a polylactic acid-based resin, and the synthetic resin is a polyolefin-based resin, so that heat sealability similar to that of a polyolefin-based resin can be imparted and liquid packaging can be achieved. Even if the contents such as fragrance and flavor that change easily are in contact, the fragrance and flavor are not significantly impaired, and the fragrance is excellent.

  (Substrate) As the substrate 11, various materials can be applied depending on the use as long as it has mechanical strength, chemical resistance, solvent resistance, manufacturability and the like with respect to the contents to be packaged and physical distribution. For example, polyester resins such as polyethylene terephthalate, polyamide resins such as nylon (trade name) 6, polyolefin resins such as polypropylene, vinyl resins such as polyvinyl chloride, cellulose films such as cellulose triacetate, polycarbonate resins, etc. There is. It may be a copolymer resin containing these resins as a main component, a mixture (including alloy), or a laminate composed of a plurality of layers. The substrate 11 may be a stretched film or an unstretched film, but a film stretched in a uniaxial direction or a biaxial direction is preferable for the purpose of improving the strength. The thickness of the substrate 11 is usually about 4 to 250 μm. Prior to coating, the substrate is subjected to easy adhesion treatment such as corona discharge treatment, plasma treatment, ozone treatment, primer (also called anchor coat, adhesion promoter, or easy adhesive) coating treatment, vapor deposition treatment, etc. Also good. Further, if necessary, for example, additives such as a lubricant, a plasticizer, a filler, an antistatic agent, and a pigment may be added for the purpose of improving and modifying the workability, lubricity and strength of the film. Good.

  As an example using a laminated body, as shown in FIG. 2, substrate 11 (PET 12 μm) / adhesive layer 13 (for dry lamination) / barrier layer 15 (Al foil 7 μm) / adhesive layer 13 (for dry lamination) ) / Resin layer 19. In addition, as shown in FIG. 3, in the layer structure consisting of the base material 11 / adhesive layer 13 (for dry lamination) / resin layer 19, as the base material 11, K-PET (vinylidene chloride coated PET film, 12 μm), An aluminum vapor deposition PET film, a silica vapor deposition PLA film, etc. can be illustrated. In short, the resin layer 19 may be formed on the surface in contact with the contents.

  (Resin layer) The resin layer is a resin composition comprising a kneaded product of a biomass resin and a synthetic resin, and biomass resin: synthetic resin = 50 to 90:50 to 10 on a mass basis. The synthetic resin component is not particularly limited, but a polyolefin resin is preferable. Examples of the polyolefin resin include LDPE, ethylene-unsaturated carboxylic acid copolymer, acid-modified polyolefin obtained by graft polymerization of carboxylic acid, and ionomer. It is preferable in terms of good points. More preferred is LDPE which is inexpensive and has good heat sealability. A combination of a polylactic acid resin excellent in biodegradability and strength and a polyolefin resin excellent in heat sealability at low cost. In addition to the resin composition consisting of biomass resin and synthetic resin constituting the resin layer, additives such as colorants, pigments, extender pigments, fillers, lubricants, plasticizers, surfactants, extenders and the like are added. Also good.

  (Biomass resin) As the biomass resin, there are starch, polylactic acid resin, microbial-produced polyester, aliphatic or aromatic polyester, etc., but microbial-produced polyester and / or aliphatic polyester are used. Biomass resins include those that biodegrade and those that do not biodegrade. Any of these may be used, preferably a biodegradable resin, and particularly preferably a polylactic acid resin in terms of biodegradability and strength.

  (Polylactic acid-based resin) Polylactic acid-based resin may contain 50% by weight or more of lactic acid component in terms of monomer mass. For example, polylactic acid, lactic acid and other aliphatic hydroxycarboxylic acids Examples thereof include a copolymer, a copolymer of lactic acid, an aliphatic polyhydric alcohol and an aliphatic polybasic acid, and a mixture of any one of the above. Examples of lactic acid include L-lactic acid, D-lactic acid, DL-lactic acid or a mixture thereof, or lactide which is a cyclic dimer of lactic acid. Specifically, a polylactic acid resin “Lacia” (trade name) manufactured by Mitsui Chemicals, Inc. can be exemplified, and as its brand, for example, H-100, H-400, H-440, H-360, H -280, 100J, H-100E, M-151S Q04, M151S Q52, and the like.

  (Synthetic Resin) The synthetic resin to be mixed with the biomass resin is not limited, but a heat-sealing polyolefin resin or a modified product thereof is preferable. Examples include PE, PP, PS, ethylene-unsaturated carboxylic acid copolymers, ethylene-unsaturated carboxylic acid ester copolymers, acid-modified polyolefins, and ionomers, which are copolymers of olefins and other monomers. Among them, any of LDPE, linear low density polyethylene (L-LDPE), ethylene-unsaturated carboxylic acid copolymer, ethylene-unsaturated carboxylic acid ester copolymer, acid-modified polyolefin, ionomer, or a combination thereof More preferred.

  (Blend ratio) The blend ratio of the resin layer 23 is biomass resin: other synthetic resin = 50 to 90:50 to 10 on a mass basis. If it is less than this range, it is less effective in reducing the environmental burden, saving resources, and creating a recycling society. If this range is exceeded, the film is not suitable for processing and it is difficult to obtain a uniform film. In addition, the ratio of biomass resin is 50% or more, which further reduces the burden on the environment and further contributes to resource saving and recycling society.

  (Mixing method) A method of blending a biomass resin and a synthetic resin (also referred to as a mixed resin) and kneading to obtain a resin composition is not particularly limited. For example, a uniaxial or multiaxial extruder, a mixer, etc. A known method may be used, and melt kneading is preferred.

  (Lamination) At least the substrate 11 / resin layer 19 and the lamination method of the substrate 11 and the resin layer 19 are not particularly limited. For example, dry lamination using a two-component curable polyurethane adhesive or the like Examples thereof include known methods such as an extrusion lamination method (referred to by those skilled in the art as extrusion coating (EC)) through an anchor coating agent.

  (EC) Extruded resin is heated and melted by an extruder, expanded and stretched in a necessary width direction with a T-die, and extruded into a curtain. The molten resin is allowed to flow down to the base material, and is sandwiched between a rubber roll and a cooled metal roll, thereby forming an extruded resin layer, adhering to the base film and laminating at the same time, and roll-to-roll winding. It is a method that can be processed with a handle and is extremely productive. The thickness of the resin layer containing the biomass resin in the extrusion lamination may be about 10 to 200 μm. If it is less than this range, the sealing strength is insufficient and liquid leakage is likely to occur. If this range is exceeded, the performance becomes excessive and wasted.

  (Dry Lamination), the dry lamination method is a method in which the resin layer 19 is formed into a resin layer film in advance and the resin layer 19 film is formed, and an adhesive dispersed or dissolved in a solvent is applied and dried, and then the laminated base material is stacked. After lamination, the adhesive is cured by aging at 30 to 120 ° C. for several hours to several days to laminate two materials. The non-solvent lamination method is a method in which the adhesive itself is applied and dried without being dispersed or dissolved in a solvent, and the laminated base material is laminated and laminated, and then aged at 30 to 120 ° C. for several hours to several days. This is a method of laminating two kinds of materials by curing the adhesive.

  (Adhesive) As an adhesive used in the dry lamination method, an adhesive that cures by heat or ionizing radiation such as ultraviolet rays or electron beams can be applied. Specific examples of thermosetting adhesives include two-component curable urethane adhesives, polyester urethane adhesives, polyether urethane adhesives, acrylic adhesives, polyester adhesives, polyamide adhesives, A polyvinyl acetate adhesive, an epoxy adhesive, a rubber adhesive, or the like can be applied, but a two-component curable urethane adhesive is preferable.

  In the dry lamination method, the adhesive composition containing the above as a main component is dissolved or dispersed in an organic solvent, and this is applied by a coating method such as roll coating or gravure coating, and the solvent is dried. Immediately after forming an adhesive layer having a thickness of about 1 to 5 μm, the adhesive is cured by aging at 30 to 120 ° C. for several hours to several days after laminating the laminated base material (resin layer 19 film). Glue with. In the case of using a non-absorbable material such as an organic polymer sheet or film, for example, an adhesive is applied to the bonding substrate side, and the substrate 11 surface is laminated. , You may make it adhere.

  (Resin layer film) As a method for forming the resin layer 19 into a film, a known inflation method, T-die method, or the like may be used. An extruded resin (a resin of the resin layer 19 = a kneaded product of a biomass resin and a synthetic resin) is used with an extruder. What is necessary is just to heat and fuse | melt, expand and expand in a desired circumference or the width direction with a round die or a T die, cool, and wind up. The thickness of the resin layer 19 is about 10 to 200 μm and may be selected according to the application. If it is less than this range, the sealing strength is insufficient and liquid leakage is likely to occur. If this range is exceeded, the performance becomes excessive and wasted. A preferable resin layer 19 is a resin layer 19 film formed by an inflation method or a T-die method that can be processed at a low temperature. Since EC processing is a high temperature processing, it is not preferable in terms of odor.

  The layered resin layer 19 having the base material 11 / resin layer 19 laminated in this manner is brought into a recycling society from the living organism to the biomass resin again through the post-use composting process and the like. It is effective for suppressing emissions, preventing global warming, and revitalizing agriculture. Further, it does not use petroleum resources or saves resources because only a small amount of use is required.

  (Packaging body) By using the laminated body 10 of the present invention, the resin layers 19 (hereinafter referred to as HS layers) are overlapped with each other and heat-sealed, and various types such as a three-side seal pouch, a four-side seal pouch, and a standing pouch are provided. As a soft package, it is used for packaging various contents.

  However, the packaging material mainly composed of plastic film permeates gas such as oxygen and water vapor, but also perfume components of food. Due to the permeation of the fragrance component, there is a problem that the fragrance is dissipated during storage, the external odor is adsorbed, and the fragrance and flavor are deteriorated. Although the fragrance retention is proportional to the gas barrier property to some extent, it does not completely match, and the permeation speed varies greatly depending on the type of film and the fragrance component. The measurement of aroma retention and flavor is generally evaluated by a sensory test. In particular, since the HS layer is in contact with the contents, it affects the flavor retention and flavor.

  In the laminate 10 of the present invention, the resin layer 19 is the innermost surface, and the HS layer is in contact with the contents, but the resin of the resin layer 19 is a kneaded product of biomass resin and synthetic resin, Excellent fragrance retention. That is, the resin layer 19 includes a biomass resin and a synthetic resin, and the biomass resin is a microorganism-producing polyester and / or an aliphatic polyester, and the blending ratio of the biomass resin and the synthetic resin is 50 to 90:50 to 10 on a mass basis. Therefore, it is possible to achieve both heat sealability and aroma retention. Preferably, the biomass resin is a polylactic acid-based resin, and the synthetic resin is a polyolefin-based resin, so that heat sealability similar to that of a polyolefin-based resin can be imparted and liquid packaging can be achieved. Even if the fragrance such as orange juice or the contents whose flavor is easy to change are in contact, the fragrance and flavor are not significantly impaired, and the fragrance is excellent. The heat sealability and scent retention will be described in the examples.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, it is not limited to this.

Example 1 First, after kneading the following resin composition, an HS layer (resin layer 19) having a thickness of 50 μm at 210 ° C. was prepared by a T-die method.
・ <Resin composition>
Polylactic acid resin (Mitsui Chemicals Co., Ltd., Lacia H-100) 60 parts LDPE resin (Nippon Polyethylene Co., Ltd., Novatec LC520) 40 parts Next, a two-component urethane adhesive is dried on PET film 12 μm (Toyobo, E5100). It is applied and dried to 4 g / m ² later, and 7 μm thick Al foil is dry-laminated. Further, the two-component urethane adhesive is dried to 4 g / m ^{2 on the} Al foil surface. After drying and laminating the HS layer, it was aged in a constant temperature room at 40 ° C. for 3 days. The laminated body 10 of Example 1 comprised from PET12micrometer / adhesive layer / Al foil 7micrometer / adhesive layer / HS layer (resin layer 19) 50micrometer was obtained.

Example 2 A laminate 10 of Example 2 was obtained in the same manner as Example 1 except that the following resin composition was used as the HS layer (resin layer 19).
・ <Resin composition>
Polylactic acid resin (Mitsui Chemicals, Lacia H-100) 80 parts LDPE resin (Nippon Polyethylene, Novatec LC520) 20 parts

(Example 3) A laminate 10 of Example 3 was obtained in the same manner as in Example 1 except that the following resin composition was used as the HS layer (resin layer 19).
・ <Resin composition>
Polylactic acid resin (Mitsui Chemicals, Lacia H-100) 50 parts LDPE resin (Nippon Polyethylene, Novatec LC520) 50 parts

(Comparative Example 1) Example except that the following resin composition was used as the HS layer (resin layer 19), and an HS layer (resin layer 19) having a thickness of 50 µm was formed at 180 ° C by the T-die method. 1 to obtain a laminate 10 of Comparative Example 1.
・ <Resin composition>
LDPE resin (Nippon Polyethylene Co., Ltd., Novatec LC520) 100 parts

(Comparative Example 2) Example except that the following resin composition was used as the HS layer (resin layer 19), and an HS layer (resin layer 19) having a thickness of 50 µm was formed at 230 ° C by the T-die method. In the same manner as in Example 1, a laminate 10 of Comparative Example 2 was obtained, but evaluation was not performed because the film formation was unstable, the thickness unevenness was large, and the difference in heat seal strength was large.
・ <Resin composition>
Polylactic acid resin (Mitsui Chemicals, Lacia H-100) 100 parts

  (Evaluation method) Evaluation was made based on aroma retention and heat sealability.

  (Aroma retaining property) Two laminates 10 of Examples 1 to 3 and Comparative Examples 1 and 2 were cut into a size of 100 mm × 100 mm, and a pouch was prepared by sealing the three sides with the resin layer 19 as the inner surface. An orange juice 50ml was filled from the opening and heat-sealed to make a four-sided seal to obtain a pouch filled with orange juice (four-side sealed bag). The pouch was stored in a thermostatic bath at 3 ° C. for 1, 2, and 3 weeks. After storage, the pouch was opened and subjected to a sensory test of the flavor of orange juice as the contents. The evaluation was such that there was almost no difference (◯ mark), some difference (X mark), large difference (XX mark), and marked difference (XXX mark). The evaluation results are shown in Table 1.

  (Heat sealability) The heat seal strength is obtained by cutting out two pieces of 15 mm width from the laminates 10 of Examples 1 to 3 and Comparative Examples 1 and 2, overlapping the two resin layer 19 surfaces, and changing the temperature. Heat sealing was performed by heating and pressurizing at 0.1 MPa for 1 second between the heated seal bar and the unheated cradle. The heat seal strength at which the two-piece laminate 10 having a width of 15 mm was peeled at a peeling angle of 90 ° (T peel) and a peeling speed of 300 mm / min was measured. The evaluation results are shown in Table 2.

  (Evaluation results) The fragrance retention was poor in the examples 1 to 3 even after 3 weeks, but in the comparative example 1, it was poor as x even in 1 week. Comparative Example 2 was not worthy of evaluation for the reasons described above. The heat sealability and Examples 1-3 were satisfactory without problems. Comparative Example 1 was also satisfactory without problems, but Comparative Example 2 was not evaluated for the reasons described above.

It is sectional drawing of the laminated body which shows one Example of this invention. It is sectional drawing of the laminated body which shows one Example of this invention. It is sectional drawing of the laminated body which shows one Example of this invention.

Explanation of symbols

10: Laminate 11: Base material 13: Adhesive layer 15: Barrier layer 19: Resin layer

Claims (2)

In a laminate having a base material and a resin layer made of a kneaded material containing a biomass resin and a synthetic resin on at least one side of the base material, the biomass resin contains 50% by weight or more of a lactic acid component, and lactic acid and others A copolymer of an aliphatic hydroxycarboxylic acid, a copolymer of lactic acid, an aliphatic polyhydric alcohol and an aliphatic polybasic acid, or a polylactic acid-based resin which is a mixture of any one of the above , and the synthesis The resin is a low-density polyethylene, linear low-density polyethylene, an ethylene-unsaturated carboxylic acid copolymer, an ethylene-unsaturated carboxylic acid ester copolymer, an acid-modified polyolefin, an ionomer, or a polyolefin-based resin that is a combination thereof. The blending ratio of the biomass resin and the synthetic resin in the resin layer is 50 to 90:50 to 10 on a mass basis, Laminate, characterized in that excellent. The laminate according to claim 1, wherein the biomass resin is a polylactic acid resin, the synthetic resin is a polyolefin resin, and orange juice is in contact with the resin layer of the laminate, A laminate characterized in that it does not impair the aroma and flavor and has excellent fragrance retention.

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