JP2018193503A - Film and packaging - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film having excellent antifogging property, transparency, heat sealing property and slipperiness between films when the contents containing water are packaged and heated or stored in a refrigerator. A film composed of an unstretched layer (S layer) containing an ethylene-based polymer and an antifogging agent (A), (B), and (C), or an ethylene-based polymer and an antifogging agent (A). A film having an unstretched layer (S layer) containing (), (B), and (C) as at least one surface layer, wherein the ethylene-based polymer has a melting point of 60 ° C. or higher and 130 ° C. or lower, and is prevented. The frosting agent (A) is a glycerin saturated fatty acid ester having a melting point of 40 ° C. or higher, the antifogging agent (B) is a glycerin fatty acid ester which is liquid at a temperature of less than 40 ° C. It is an ethylene oxide adduct with a sex balance (HLB) of 9.0 or more, and the mass ratio of the antifogging agent (A) to the total mass of the antifogging agents (A), (B), and (C) is 5%. More than 60%. [Selection diagram] None

Description

  The present invention relates to a film and a package used for the purpose of packaging contents with a plastic film.

  With the expansion of the market for fresh foods such as meat, fresh fish, and fruits and diversification of consumer needs, film for food packaging has transparency that enables visual inspection of contents, oxygen and water vapor barrier properties, pinhole resistance, Various characteristics such as heat resistance are required.

In these food packaging films, a sealant layer is generally provided in the innermost layer of the film in order to heat seal the films and wrap the contents. In addition to heat sealability and transparency, the sealant layer wraps moisture-containing contents and prevents condensation on the inner surface of the film when heated with a microwave oven, boil, retort, etc., or stored refrigerated. Haze is required, and these required levels are extremely high.
This problem can be solved by adding a highly hydrophilic surfactant, anti-fogging agent, etc. to the sealant film or coating the film surface. On the other hand, the formed film is wound or unwound or slitted. In the process to perform, it has become a problem that the outer surface and inner surface of a film will block.

  As a technique for imparting both antifogging properties and slipperiness to a film, for example, Patent Document 1 includes an intermediate layer made of a propylene-based resin, a linear low density polyethylene, a diglycerin fatty acid ester, and an ethylene oxide adduct. It discloses a stretch packaging film comprising a laminated film having a layer containing an antifogging agent on both surfaces, and a corona discharge treatment applied to the surface layer containing the antifogging agent.

  Further, Patent Document 2 includes a package that includes both surface layers containing an antifogging agent in an ethylene-vinyl acetate copolymer, and the surface is hydrolyzed using a humidifying spray facility or the like to improve the slipperiness of the film. A stretch film is disclosed. However, this technique requires a post-process at the time of film formation, and requires addition of special equipment.

  Patent Document 3 discloses a laminate mainly composed of a polyolefin resin formed in one layer of a polypropylene-based biaxially stretched film. The surface of the heat seal layer has antifogging properties and is free from organic polymer fine particles. A packaging film containing a predetermined amount of active fine particles is disclosed. This technology aims to express slipperiness in the film structure without using post-processes or special equipment, but the fine particles on the film surface may interfere with long-term antifogging performance. Concerned.

  Moreover, in patent document 4, as a method which does not use a special process, an inorganic filler, etc., it has at least 3 layers and the total content of an antifogging agent is 0.1-0.1 by combining a specific antifogging agent. A polyolefin-based multilayer film characterized by a low addition amount of less than 1.0% by weight is disclosed. However, depending on the film production process, aging treatment is necessary, and since the addition amount is low, there is a concern that the anti-fogging performance may not be maintained for a long time.

JP 2001-287325 A JP 2002-86645 A Japanese Patent Laid-Open No. 2003-237827 JP 2009-101606 A

  The present invention has been made in view of the above problems, and the object of the present invention is excellent in anti-fogging properties both when packaging and heating the moisture-containing contents and when refrigerated and being transparent, The object is to provide a film excellent in heat sealability and slipperiness between films.

The present inventors diligently studied the above-mentioned problems and have completed the present invention.
That is, the present invention provides a film comprising an unstretched layer (S layer) containing an ethylene polymer and an antifogging agent (A), (B), and (C), or an ethylene polymer and an antifogging agent. A film having an unstretched layer (S layer) containing (A), (B), and (C) as at least one surface layer, wherein the ethylene polymer has a melting point of 60 ° C. or higher and 130 ° C. or lower. The antifogging agent (A) is a glycerin saturated fatty acid ester having a melting point of 40 ° C. or higher, the antifogging agent (B) is a liquid glycerin fatty acid ester at a temperature of less than 40 ° C., and the antifogging agent (C) is a parent. It is an ethylene oxide adduct having an oily hydrophilic balance (HLB) of 9.0 or more, and the mass ratio of the antifogging agent (A) to the total mass of the antifogging agents (A), (B), and (C) is A film characterized by being 5% or more and less than 60% To.

According to the present invention, excellent anti-fogging that does not fog in a wide range of temperature conditions from when the high-temperature steam at the time of performing microwave processing, boiling, or retort treatment touches the film surface to when storing at low temperature such as a refrigerator. A film having properties is obtained. Moreover, transparency and heat sealability are also good.
Furthermore, because of excellent slipperiness between films, blocking is unlikely to occur, and secondary processing such as roll unwinding, slitting, printing, bag making, etc. can be performed well, and it is suitable as a film for packaging applications. Can be used.

Hereinafter, the film of the present invention (hereinafter referred to as “the present film”) as an example of the embodiment of the present invention will be described. However, the scope of the present invention is not limited to the embodiments described below.
The film of the present invention is composed of a film comprising an unstretched layer (S layer) containing an ethylene polymer and an antifogging agent (A), (B), and (C), or an ethylene polymer and an antifogging agent. It is a film having an unstretched layer (S layer) containing clouding agents (A), (B), and (C) as at least one surface layer. When the film of the present invention is formed of a multilayer of an S layer and another resin layer, the S layer having a sealant function is positioned on the contents side to be packaged, and the other resin layer is positioned on the outside air layer side. To do.

<Ethylene polymer>
The ethylene polymer used for the S layer is not particularly limited as long as it has a melting point of 60 ° C. or higher and 130 ° C. or lower. Examples of the ethylene polymer include ultra-low density polyethylene, low density polyethylene, medium density polyethylene, high density polyethylene, ethylene-propylene copolymer, ethylene-1-butene copolymer, and ethylene-4-methyl-1- Copolymers of ethylene and α-olefins having 3 to 18 carbon atoms, such as pentene copolymer, ethylene-1-hexene copolymer, ethylene-1-octene copolymer, and ethylene-1-decene copolymer Ethylene-conjugate such as ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer, ethylene-butadiene copolymer, ethylene-isoprene copolymer Examples thereof include a diene copolymer and an ethylene-nonconjugated diene copolymer. Among these, low density polyethylene, ethylene-α-olefin copolymer, ethylene-vinyl acetate copolymer, ethylene- (meth) acrylate copolymer, and the like are preferably used. By using these, the compatibility with the antifogging agent is excellent, the antifogging performance is easily exhibited, and the transparency of the film is excellent. In addition, an ethylene-type polymer may be used by 1 type, and 2 or more types may be mixed and used for it.

The melting point of the ethylene polymer used for the S layer is 60 ° C. or higher and 130 ° C. or lower, the lower limit is preferably 80 ° C. or higher, and the upper limit is preferably 120 ° C. or lower. If the melting point is within the above range, the film has heat resistance and excellent heat sealability.
The melting point is the crystal melting peak temperature measured according to JIS K 7121 using a differential scanning calorimeter at a heating rate of 10 ° C./min.

The density (JIS K7112) of the ethylene polymer used for the S layer is preferably 900 to 950 kg / m ³ . If it is this range, processability, such as drawdown property, draw resonance, and drawability, can be stably maintained.

  The melt flow rate (MFR) (JIS K7210-1, 190 ° C., 2.16 kg load) of the ethylene polymer used for the S layer is preferably 0.5 to 20 g / 10 minutes, and 1.0 to 10 g / 10 minutes. Is more preferable. If it is this range, the moldability in extrusion molding by T-die or inflation, extrusion lamination, etc. will be favorable, and preparation of a film, a sheet, etc. will be easy.

In addition, S layer may mix | blend other resin suitably in the range which does not impair the effect of this invention as needed other than an ethylene-type polymer. Specific examples of other resins include propylene resins such as propylene homopolymers and propylene-α-olefin copolymers, styrene resins, vinyl chloride resins, polyester resins, polycarbonate resins, polyamide resins, and polyacetals. Resin, polyethylene oxide resin, cyclic olefin resin, polyurethane resin, silicone resin and the like.
The blending of the other resin is preferably less than 40% by mass and more preferably less than 20% by mass with respect to the total amount of the ethylene polymer and the other resin. If it is this range, an ethylene-type polymer will become a main component, and it has the characteristics as sealants, such as a heat seal characteristic, and can improve mechanical characteristics, such as pinhole resistance, and heat resistance.

<Anti-fogging agent (A)>
The antifogging agent (A) used for the S layer is a glycerin saturated fatty acid ester having a melting point of 40 ° C. or higher, and is preferably a powder at normal temperature.
If it is glycerin saturated fatty acid ester with melting | fusing point of 40 degreeC or more, when high temperature vapor | steam touches a film, an antifogging agent can transfer to a film surface rapidly, and initial stage antifogging property can be expressed. Further, when the powder is a glycerin saturated fatty acid ester, the antifogging agent tends to stay on the surface of the film, and it can be expected to suppress blocking between films generated by bleeding out of the liquid antifogging agent component in the film. . The melting point is the crystal melting peak temperature measured according to JIS K7121 using a differential scanning calorimeter at a heating rate of 10 ° C./min.

  Glycerin saturated fatty acid ester is obtained by esterification reaction of glycerin and saturated fatty acid. Specific examples of the fatty acid constituting the glycerin saturated fatty acid ester having a melting point of 40 ° C. or higher include lauric acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, arachidic acid and the like. Among these, a saturated fatty acid ester having 12 to 20 carbon atoms is preferably used. In addition, these saturated fatty acids may be used independently and can also be used in combination of 2 or more type.

  Specific examples of commercially available anti-fogging agents (A) include, for example, Richemal S-100 (monoglycerin stearate), Richemal S-71D (diglyceryl stearate), Poem M-200 (glycerin) manufactured by Riken Vitamin Co., Ltd. Monocaprate), Poem M-300 (glycerin monolaurate) and the like.

<Anti-fogging agent (B)>
The anti-fogging agent (B) used for the S layer is a glycerin fatty acid ester that is liquid at a temperature of less than 40 ° C., a glycerin fatty acid ester having a melting point of less than 40 ° C., a temperature that does not have a melting point and is less than 40 ° C. Examples include glycerin fatty acid esters that are liquids, viscous liquids, pastes, and waxes.
Moreover, it is preferable that the value of lipophilic hydrophilic balance (HLB) is 4-8, and 5-8 are more preferable.
By using glycerin fatty acid ester which is liquid at a temperature of less than 40 ° C., the moisture-containing contents are sealed and packaged using this film, and even when stored in a refrigerated environment of 0 to 10 ° C., an antifogging agent Can be quickly transferred to the film surface, thus exhibiting antifogging properties. When the HLB value is in the range of 4 to 8, the antifogging agent (C) described later, that is, a matrix resin exhibiting hydrophobicity such as polyolefin when used in combination with an ethylene oxide adduct having an HLB of 9.0 or more. Further, compatibility with antifogging agents having relatively high lipophilicity, improvement of surface wettability, and antifogging properties and transparency are further improved.
The melting point is the crystal melting peak temperature measured according to JIS K 7121 using a differential scanning calorimeter at a heating rate of 10 ° C./min. The lipophilic hydrophilic balance (HLB) value is calculated from the component composition.

  Glycerin fatty acid ester is obtained by esterification reaction of glycerin and fatty acid. Specific examples of the fatty acid constituting the glycerin fatty acid ester include diglycerin laurate, diglycerin oleate, decaglycerin laurate, decaglycerin oleate, and polyglycerin polyricinoleate. Of these, saturated or unsaturated fatty acids having 12 to 20 carbon atoms are preferably used. These fatty acids may be used alone or in combination of two or more.

  Specific examples of commercially available anti-fogging agents (B) include Riquemar O-71D (diglycerin oleate) and Riquemar L-71D (diglycerin laurate) manufactured by Riken Vitamin Co., Ltd., and MCA manufactured by Sakamoto Pharmaceutical Co., Ltd. -150 (diglycerin caprylate) and the like.

<Anti-fogging agent (C)>
The antifogging agent (C) used for the S layer is an ethylene oxide adduct having a lipophilic hydrophilic balance (HLB) of 9.0 or more, and the HLB is preferably 10.0 or more, more preferably 11.0 or more. Preferably it is 12 or more.
If the HLB is 9.0 or more, the hydrophilicity is sufficient and the surface tension with the water on the surface of the S layer can be lowered, so that the water droplets on the surface of the S layer become a film and improve the antifogging property. Is possible. Further, the combined use of the antifogging agent (A) and the antifogging agent (B) increases the affinity of the ethylene oxide adduct to the ethylene polymer of the S layer, so that the antifogging agent on the surface of the S layer The transition becomes easy, and the anti-fogging property is more excellent due to the synergistic effect.
The lipophilic hydrophilic balance (HLB) value is calculated from the component composition.

  The ethylene oxide adduct is a compound obtained by adding ethylene oxide to alcohol, fatty acid, esters thereof, fats and oils, and is generally known as a nonionic surfactant. The desired HLB is adjusted by adjusting the chain length of the polymerized portion of ethylene oxide. Specific examples of the ethylene oxide adduct include polyoxyethylene alkyl ether, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene fatty acid ester and the like. Specific examples of the polyoxyethylene sorbitan fatty acid ester and the fatty acid constituting the polyoxyethylene fatty acid ester are the same as those listed as examples of the fatty acid constituting the monoglycerin fatty acid ester, and among them, the number of carbon atoms is 12 to Twenty saturated or unsaturated fatty acids are preferably used. These fatty acids may be used alone or in combination of two or more.

  Specific examples of commercially available anti-fogging agents (C) include Riquemar O-852 (polyoxyethylene sorbitan trioleate), Riquemar B-205 (polyoxyethylene alkyl ether), Kao Corporation manufactured by Riken Vitamin Co., Ltd. Examples include Leodole TW series (polyoxyethylene sorbitan fatty acid ester) and Emanone series (polyoxyethylene fatty acid ester).

  The S layer of the present film can contain other antifogging agents as long as the properties are not impaired. Examples thereof include alkylene glycol fatty acid esters such as sorbitan fatty acid ester, ethylene glycol fatty acid ester, and propylene glycol fatty acid ester. The addition amount of these antifogging agents is not particularly limited, and can be appropriately determined within a range that does not hinder the desired physical properties of the present invention.

<Content of antifogging agent>
The content of each of the antifogging agents (A), (B), and (C) is preferably in the range of 0.1% by mass or more and 5.0% by mass or less with respect to the total mass of the S layer. The lower limit is more preferably 0.2% by mass or more, and further preferably 0.5% by mass or more. The upper limit is more preferably 4.0% by mass or less, and further preferably 3.0% by mass or less.
The total mass of the antifogging agents (A), (B), and (C) is preferably in the range of 1.0% by mass to 8.0% by mass with respect to the total mass of the S layer. The lower limit is more preferably 2.0% by mass or more. The upper limit is more preferably 6.0% by mass or less, and still more preferably 5.0% by mass or less.
Anti-fogging agent (A), (B), and (C) each containing mass ratio and total containing mass ratio are within the above ranges, so that the film has anti-fogging properties in a wide range of operating temperatures such as low temperature, normal temperature, and high temperature. In addition, the heat sealability and transparency are excellent.

  The anti-fogging agent moves from the inside of the S layer to the surface and exhibits anti-fogging performance, but one surface layer of the film is composed of the S layer, and the opposite surface layer is composed of the other resin layer. In the case of, when the film is rolled up and the S layer and the other resin layer are in close contact, the antifogging agent of the S layer is transferred to the surface of the other resin layer or transferred into the other resin layer. Can happen. In the case of a multilayer film, an S layer having a sealant function is positioned on at least one surface layer on the contents to be packaged to produce a package. It is important that the antifogging agent of the S layer does not move to the other resin layer side even when wound into a film roll and has a sufficient amount of antifogging agent inside or on the surface of the S layer. Therefore, the total mass of the antifogging agents (A), (B), and (C) in the S layer after the film is rolled is 1.0 mass% or more to 8.0 mass% with respect to the total mass of the S layer. The lower limit is preferably 2.0% by mass or less, and more preferably 2.0% by mass or more.

The mass ratio of the antifogging agent (A), which is a glycerin saturated fatty acid ester having a melting point of 40 ° C. or higher, is 5 with respect to the total mass of the antifogging agents (A), (B), and (C) in the S layer. It is more than mass% and less than 60 mass%. The lower limit is preferably 10% by mass or more, and more preferably 15% by mass or more. The upper limit is preferably 50% by mass or less, and more preferably 40% by mass or less.
If the content ratio of the antifogging agent (A) is 5% by mass or more based on the total mass of the antifogging agents (A), (B), and (C), the film antifogging property is not impaired, If slipperiness can be imparted and the amount is less than 60% by mass, transparency due to excessive bleed out and deterioration of the film appearance are unlikely to occur, and good heat sealability and antifogging properties in a refrigerated environment Can be obtained.

  The qualitative and quantitative determination of each anti-fogging agent in the S layer can be performed by cutting out the S layer and analyzing it with an extraction-liquid chromatograph or a pyrolysis gas chromatograph.

<Other additives>
The S layer and other resin layers of the present film can contain other additives as long as the properties are not impaired. Examples include colorants, inorganic fillers, organic fillers, ultraviolet absorbers, light stabilizers, heat stabilizers, antioxidants, lubricants, hydrolysis inhibitors, antistatic agents, plasticizers, flame retardants, and the like. it can. The addition amount of these additives is not particularly limited, and can be appropriately determined within a range that does not hinder the desired physical properties of the present invention.

<Method for producing this film>
The structure of this film is a film comprising the above-mentioned unstretched S layer or a film having the unstretched S layer as at least one surface layer. That is, it may be an unstretched single layer film consisting of only the S layer, or a multilayer film composed of another resin layer and an unstretched S layer.

  When the film is rolled to form a film roll, it is sufficient that the roll is not misaligned during storage, and general-purpose winding conditions and winding hardness of about 75 to 95 degrees may be used. In such a general roll state, the present film is difficult to block and can easily be unrolled, and the film after roll unwinding has good antifogging properties and transparency.

  The method for producing the unstretched monolayer film is not particularly limited, and specific examples include a T-die method and an inflation method.

The method for producing the multilayer film is not particularly limited as long as the unstretched S layer can be located on one surface.
For example, the S layer can be designed and manufactured as one surface layer by co-extrusion using a feed block method, a multi-manifold die, or a combination thereof by an extrusion casting method using a T die, an inflation method, etc. Good.
In addition, after producing an unstretched single layer film made of S layer and a film made of other resin layers, both films are bonded together by dry lamination method, wet lamination method, sand lamination method, thermal lamination method, etc. A multilayer film may be used. Moreover, it is good also as a multilayer film by extrusion-laminating the material which comprises S layer to the film which consists of another resin layer. When a plurality of films made of other resin layers are used, they are laminated so that the S layer is located on one surface.
When laminating, various adhesives such as various surface treatments such as anchor coating and corona discharge treatment, urethane adhesives, acrylic adhesives, and polyester adhesives can be used as necessary.

<Film consisting of other resin layers>
When using a film composed of another resin layer, it may be either a single layer film or a multilayer film, and may be any of an unstretched film, a uniaxially stretched film, and a biaxially stretched film, a polyolefin resin layer, a polyester resin layer It can be composed of various resin layers such as a polyamide-based resin layer. They also have various required characteristics such as handling properties during manufacturing, transport and secondary processing, oxygen gas barrier properties, water vapor barrier properties, impact resistance, and pinhole resistance in packaging applications for food, medical and industrial parts. Can be selected. From the viewpoint of versatility for packaging applications, when it is multilayered with a polyester resin layer and a polyamide resin layer, it can be suitably used for various packaging as a film having an unstretched S layer on the surface.

Moreover, it can use for this film by adding a contact bonding layer, a vapor deposition layer, a printing layer, an antistatic layer etc. to the film which consists of another resin layer using a well-known coating method, a vapor deposition method, and a printing method.
In particular, since gas barrier properties are required for the long-term maintenance of the contents of food, pharmaceuticals, and industrial products, the gas barrier layer may be disposed on a film made of another resin layer. preferable. Specific examples of the gas barrier layer include a melt-extruded layer made of polyvinyl alcohol (PVA), saponified ethylene-vinyl acetate copolymer (EVOH), metaxylenediamine polyamide (MXD-Ny), polyvinylidene chloride (PVDC), and the like. And a vapor deposition layer of aluminum, alumina, silica or the like. For example, the gas barrier layer is arranged on the inner side in the film configuration as in the [S layer / gas barrier layer / other resin layer] and [S layer / other resin layer / gas barrier layer / other resin layer] configurations. It is preferable to provide a stable gas barrier property.

  Further, from the viewpoint of the antifogging property of the film due to the S layer, it is preferable to dispose a resin layer other than the polyamide resin layer on the film surface layer opposite to the S layer in the film configuration. For example, when a polyester resin such as polyethylene terephthalate (PET) or a polyolefin resin such as polypropylene (PP) is arranged, the antifogging property under low to high temperature conditions is good even when the roll-wrapped film is unrolled. Demonstrated. The reason for this phenomenon is not clear, but when the functional group polarity of the other resin layer on the film surface is high, the anti-fogging agent is formed when the S layer on the both surface layers of the film and the other resin layer are in close contact with each other. Is considered to be transferred from the S layer to the surface and transferred or transferred to the surface of another resin layer. Therefore, when using a polyamide (PA) layer such as nylon 6 (Ny6) for pinhole resistance and gas barrier properties of the film, for example, [S layer / deposition layer / biaxially stretched PA film / biaxially stretched] It is preferable to arrange the PA layer on the inner side of the film structure, such as [PET film] and [S layer / PA / EVOH / PO].

<Thickness>
In the case of an unstretched monolayer film consisting of only the S layer, 10 to 100 μm is preferable and 15 to 50 μm is more preferable. If it is 10 μm or more, sufficient strength can be obtained with respect to the elongation, bending, load resistance, etc. of the film. Moreover, if it is 100 micrometers or less, sufficient heat seal intensity | strength can be obtained.
In the case of a multilayer film composed of another layer and an unstretched S layer, the thickness of the S layer is preferably 1 to 50 μm, more preferably 3 to 20 μm. If it is such a thickness range, sufficient heat-sealing property will be obtained in a multilayer film. The thickness of the other layers is not particularly limited as long as the function of those layers can be expressed, but since it is used for packaging, it has sufficient flexibility, bending resistance, strength, and economical point. Therefore, 1 to 50 μm is preferable, and 3 to 25 μm is more preferable. 10-100 micrometers is preferable and, as for the total thickness of a multilayer film, 15-50 micrometers is more preferable.
For example, when a film having a gas barrier layer is extruded and laminated with a resin constituting the S layer to form a multilayer film, the thickness of the film having the gas barrier layer is 5 to 25 μm, and the thickness of the S layer is 3 to 20 μm. preferable.

  This film is a plastic film for packaging contents, and has the following characteristic functions in addition to sealant properties (heat seal properties).

<Heat sealability>
This film uses an ethylene polymer having a melting point of 60 ° C. or higher and 130 ° C. or lower for the S layer, so that the S layers of the present film are opposed to each other, or from the ethylene polymer of other packaging films. In the case of sealing with facing the layer, it has excellent heat sealability.
For example, from the viewpoint of the total film thickness, etc., if the setting conditions are appropriately selected in the range of 90 to 160 ° C. and 1 to 5 seconds and heat sealing is performed, sufficient adhesive strength (film peel strength) 3N / 15 mm for packaging applications More than width can be obtained.

<Anti-fogging property>
In this film, the antifogging agent contained in the S layer moves to the surface of the S layer on the content side of the package, so that moisture hardly condenses on the surface of the S layer, or a water film forms on the film surface. The film is not accumulated in a lens shape, but is formed evenly on one surface. As a result, the film is not fogged and the contents visibility is improved.
Generally, in a form in which the contents are packaged, the vapor inside the package tends to condense on the contents-side surface of the film due to cold and warm outside air in a low temperature environment such as refrigerated storage at about 0 ° C to 5 ° C. Further, in a high temperature environment immediately after heating the package with a boil, a microwave oven, or the like, the film rapidly becomes cloudy due to a phenomenon in which steam is filled with moisture derived from the contents inside the package.
Therefore, antifogging properties over a wide temperature range and immediate antifogging properties are required, and in this film, as described above, the S layer contains antifogging agents (A), (B), (C), In addition, by controlling the ratio of the antifogging agent (A), it is possible to exhibit excellent antifogging properties in a wide temperature environment of low temperature, normal temperature, and high temperature, and steam is rapidly generated in a high temperature environment. Even when it becomes cloudy, excellent antifogging properties can be exhibited.

<Slipperiness>
This film contains the antifogging agent (A) which is a saturated glycerin fatty acid ester having a melting point of 40 ° C. or higher in the S layer, so that the antifogging agent (A) is deposited in a solid state on the film surface at room temperature, The contact area between them can be reduced, and the slipperiness of the surface of the S layer is improved. In other words, it is possible to provide both slipperiness and antifogging properties without adding other lubricants.
In addition, due to the slipperiness of the surface of the S layer, in the case of a non-stretched single layer film only from the S layer, or in the case of a multilayer film composed of other layers and an unstretched S layer, blocking occurs when the film is rolled. It is difficult to generate, and roll unwinding and slitting of the film can be performed satisfactorily, and as a result, secondary processing such as printing and bag making can be performed efficiently.
In the case of a multilayer film, even if a lubricant is contained in the film surface layer opposite to the S layer, blocking occurs if the slipperiness of the S layer surface is insufficient.

<Transparency>
The transparency of the film is preferably 10% or less of the total haze value measured in accordance with JIS K7136, when the film has a thickness of 20 μm, from the viewpoints of aesthetics and contents visibility. The following is more preferable. The lower limit of the total haze value is not particularly limited, and is preferably as small as possible. When the total haze value is within the range, the film is excellent in transparency, and the contents are highly visible when used as a packaging film.
Since the transparency is deteriorated depending on the compatibility and content of the antifogging agent with respect to the resin composition of the S layer, the above antifogging agent ( The combination of A), (B), and (C) is essential.

<Wettability>
This film contains an antifogging agent (C) which is an ethylene oxide adduct having a high hydrophilicity of HLB 9.0 or higher in the S layer, so that the interfacial tension with water decreases on the outside air side surface of the S layer, Good wettability with water. Therefore, in the present film, the moisture on the surface of the S layer spreads uniformly without forming fine water droplets or lenses, so that the contents can be clearly seen.

<Application>
This film has excellent anti-fogging properties in a wide range of temperatures, including refrigerated temperatures, normal temperatures, and high temperatures where steam is generated, and it also excels in transparency, heat sealability, and slipperiness. -It can use suitably as a sealant of the various packaging films with respect to the content to be retorted, especially a food packaging film.
Examples of the contents include raw meat, fresh seafood, processed meat products, marine products, confectionery, side dishes, pickles, konjac and other viscous products, fresh vegetables, cheese, and the like.
The form of the packaging is not particularly limited, and examples thereof include a lid material that is heat-sealed with the peripheral edge portion of the tray, and a bag body such as pillow packaging or three-side sealed packaging.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not restrict | limited by the following Example.

<Materials used>
The melting point of the following materials is a value measured according to JIS K7121. The density is a value measured according to JIS K7112. The melt flow rate (MFR) is a value measured according to JIS K7210-1 (190 ° C., 2.16 kg load).
The oxygen transmission rate is a value measured under the conditions of 23 ° C. and 0% RH based on JIS K7126-2 method. The water vapor transmission rate is a value measured under conditions of 40 ° C. and 90% RH based on JIS K7129.

(Ethylene polymer)
PE-1: Low density ethylene (LDPE), melting point 106 ° C., density 918 kg / m ³ , MFR 7.0 g / 10 min
PE-2: ethylene-vinyl acetate copolymer (EVA), VA content 28 mass%, melting point 72 ° C., density 950 kg / m ³ , MFR 6.0 g / 10 min
PE-3: ethylene-methyl acrylate copolymer (EMA), MA content 20% by mass, melting point 77 ° C., density 942 g / m ³ , MFR 6.0 g / 10 min

(A) Glycerin saturated fatty acid ester a-1: Monoglycerol monostearate, powder at room temperature, melting point 67 ° C., HLB value 4.3
a-2: Diglycerin stearate, powder at normal temperature, melting point 61 ° C., HLB value 5.7

(B) Polyglycerin fatty acid ester b-1: Diglycerin oleate, liquid at normal temperature, HLB value 5.7
b-2: Diglycerin laurate, waxy at room temperature, melting point about 34 ° C., HLB value 7.3

(C) Ethylene oxide adduct c-1: Polyoxyethylene sorbitan trioleate, liquid at room temperature, HLB value 11.0
c-2: polyoxyethylene alkyl ether, liquid at room temperature, HLB value 12.0
c-3: polyoxyethylene glycerol monostearate, waxy at room temperature, HLB value 8.7

(Film having a gas barrier layer)
G-1: PVDC-coated biaxially stretched PP film, 25 μm thickness, oxygen permeability 15 ml / (m ² · 24 h · atm), water vapor permeability 1.0 g / (m ² · 24 h)
G-2: PVDC-coated biaxially stretched PET film, 16 μm thick, oxygen transmission rate 80 ml / (m ² · 24 h · atm), water vapor transmission rate 15 g / (m ² · 24 h)
G-3: Aluminum-deposited biaxially stretched PP film, 15 μm thick, oxygen permeability 40 ml / (m ² · 24 h · atm), water vapor permeability 0.5 g / (m ² · 24 h)
G-4: Biaxially stretched PET film deposited with aluminum, 12 μm thickness, oxygen permeability 0.7 ml / (m ² · 24 h · atm), water vapor permeability 0.7 g / (m ² · 24 h)
G-5: biaxially stretched PET film deposited with silica, 12 μm thick, oxygen permeability 5 ml / (m ² · 24 h · atm), water vapor permeability 0.5 g / (m ² · 24 h)
G-6: PP / EVOH / PP coextruded biaxially stretched film, 20 μm thick, oxygen permeability 3 ml / (m ² · 24 h · atm), water vapor permeability 6 g / (m ² · 24 h)
G-7: PVA-coated biaxially stretched PP film, 20 μm thick, oxygen permeability 10 ml / (m ² · 24 h · atm), water vapor permeability 4.1 g / (m ² · 24 h)
G-8: PVDC-coated biaxially stretched Ny6 film, 18 μm thick, oxygen permeability 30 ml / (m ² · 24 h · atm), water vapor permeability 6 g / (m ² · 24 h)
G-9: Ny6 / EVOH / Ny6 coextruded biaxially stretched film, 17 μm thick, oxygen permeability 6 ml / (m ² · 24 h · atm), water vapor permeability 50 g / (m ² · 24 h)

(Other resin layers)
PBT: Polybutylene terephthalate resin EVOH: Saponified ethylene-vinyl acetate copolymer, ethylene content 32 mol%
Ny6: Nylon 6 resin Adhesive resin: Maleic anhydride modified polyolefin resin

Example 1
PE-1, a-1, b-1, and c-1 were weighed at a mixing mass ratio of 97.5: 0.5: 1.0: 1.0, and these were measured with a lab plast mill manufactured by Toyo Seiki Seisakusho. After kneading for 5 minutes under the conditions of a test temperature of 200 ° C. and a rotation speed of 80 rpm, using a laminator device, a molten resin is poured between the biaxially stretched PET films, and a metal roll set so that the roll temperature is 200 ° C. Extrusion was performed while niping between rubber rolls at a pressure of ² kg / cm ² , and then the biaxially stretched PET film on both sides was peeled off to obtain an unstretched film consisting only of a sealant layer having a thickness of 20 μm.

(Example 2)
In the same manner as in Example 1 except that PE-1, a-1, b-1, and c-1 were weighed at a mixing mass ratio of 97.0: 1.0: 1.0: 1.0. Films were made and evaluated.

Example 3
In the same manner as in Example 1 except that PE-1, a-1, b-1, and c-1 were weighed at a mixing mass ratio of 96.0: 2.0: 1.0: 1.0. Films were made and evaluated.

(Example 4)
Except that PE-1, a-1, b-2, and c-1 were weighed at a mixing mass ratio of 97.0: 1.0: 1.0: 1.0, the same method as in Example 1 was used. Films were made and evaluated.

(Example 5)
In the same manner as in Example 1, except that PE-1, a-1, b-2, and c-2 were weighed in a mixing mass ratio of 97.0: 1.0: 1.0: 1.0. Films were made and evaluated.

(Example 6)
In the same manner as in Example 1 except that PE-1, a-1, b-2, and c-2 were weighed in a mixing mass ratio of 96.0: 1.0: 1.0: 2.0. Films were made and evaluated.

(Example 7)
Except that PE-1, a-2, b-2, and c-1 were weighed at a mixing mass ratio of 97.0: 1.0: 1.0: 1.0, the same method as in Example 1 was used. Films were made and evaluated.

(Example 8)
Except that PE-1, a-2, b-2, and c-2 were weighed at a mixing mass ratio of 96.0: 2.0: 1.0: 1.0, the same method as in Example 1 was used. Films were made and evaluated.

Example 9
In the same manner as in Example 1, except that PE-2, a-1, b-1, and c-1 were weighed at a mixing mass ratio of 97.0: 1.0: 1.0: 1.0. Films were made and evaluated.

(Example 10)
The same method as in Example 1 except that PE-3, a-1, b-1, and c-1 were weighed at a mixing mass ratio of 97.0: 1.0: 1.0: 1.0. Films were made and evaluated.

(Comparative Example 1)
A film was prepared and evaluated in the same manner as in Example 1 except that PE-1, b-1, and c-1 were weighed at a mixing mass ratio of 97.0: 1.5: 1.5.

(Comparative Example 2)
In the same manner as in Example 1, except that PE-1, a-1, b-1, and c-1 were weighed in a mixing mass ratio of 95.0: 3.0: 1.0: 1.0. Films were made and evaluated.

(Comparative Example 3)
A film was prepared in the same manner as in Example 1 except that PE-1, a-1, and c-1 were weighed at a mixing mass ratio of 97.0: 1.0: 1.0: 1.0. evaluated.

(Comparative Example 4)
A film was produced in the same manner as in Example 1 except that PE-1, a-1, a-2, and c-1 were weighed at a mixing mass ratio of 97.0: 1.5: 1.5. evaluated.

(Comparative Example 5)
A film was prepared and evaluated in the same manner as in Example 1 except that PE-1, a-1, and b-1 were weighed at a mixing mass ratio of 97.0: 1.5: 1.5.

(Comparative Example 6)
A film was prepared and evaluated in the same manner as in Example 1 except that PE-1 and c-1 were weighed at a mixing mass ratio of 97.0: 3.0.

(Comparative Example 7)
In the same manner as in Example 1, except that PE-1, a-1, b-1, and c-3 were weighed at a mixing mass ratio of 97.0: 1.0: 2.0: 1.0. Films were made and evaluated.

(Example 11)
PE-1, a-1, b-1, and c-1 were weighed and blended at a mixing mass ratio of 96.5: 0.5: 1.5: 1.5, using a twin screw extruder. Extruded into a strand at a set temperature of 200 ° C. From this strand, pellets for sealant were produced using a pelletizer, and then G-1 was fed out from the first paper feeding unit of the extrusion laminator, and the pellets for sealant layer were placed at 270 ° C. on the gas barrier layer surface of G-1. A monoaxial screw was melt-extruded from the T die to form an unstretched sealant layer having a thickness of 20 μm, and an extruded laminate gas barrier multilayer film was produced.
This multilayer film was wound into a roll shape, and evaluated by standing for 72 hours at room temperature and normal pressure while keeping the roll horizontal in the film width direction in a roll winding hardness of 90 degrees.

(Example 12)
A film was produced and evaluated in the same manner as in Example 11 except that G-1 was replaced with G-2.

(Reference Example 1)
A film was prepared and evaluated in the same manner as in Example 11 except that G-1 was replaced with G-3.

(Reference Example 2)
A film was prepared and evaluated in the same manner as in Example 11 except that G-1 was replaced with G-4.

(Example 13)
A film was prepared and evaluated in the same manner as in Example 11 except that G-1 was replaced with G-5.

(Example 14)
A film was prepared and evaluated in the same manner as in Example 11 except that G-1 was replaced with G-6.

(Example 15)
A film was prepared and evaluated in the same manner as in Example 11 except that G-1 was replaced with G-7.

(Example 16)
A film was prepared and evaluated in the same manner as in Example 11 except that G-1 was replaced with G-8.

(Example 17)
A film was prepared and evaluated in the same manner as in Example 11 except that G-1 was replaced with G-9.

(Example 18)
In the same manner as in Example 11, pellets for sealant were prepared, and an unstretched coextruded multilayer film having the following layer constitution was prepared and evaluated using a single screw and a feed block type coextrusion die.
PBT layer (15 μm thickness) / adhesive resin layer (5 μm thickness) / EVOH layer (10 μm thickness) / Ny6 (10 μm thickness) / adhesive resin (5 μm thickness) / sealant layer (10 μm)

<Evaluation method>
About the sample obtained by the Example and the comparative example, it measured and evaluated with the following method and the result was shown to Tables 1-3.

(1) Heat seal strength Two strips having a length of 100 mm and a width of 15 mm are cut out from the film and the surfaces of the sealant layers are overlapped with each other, and one end of the short side is set at a set temperature of 150 ° C. using a heat seal machine at 23 ° C. A test piece was obtained by heat sealing at 2 kg / cm ² for 2 seconds. About this test piece, with the heat seal portion at the center, both ends are attached to both grips of a tensile tester, tensile stress is applied until it breaks at a peeling angle of 180 degrees and a peeling speed of 200 mm / min, and the maximum stress is heated. The seal strength (N / 15 mm width) was used.
A heat seal strength of 3 N / 15 mm width or more is useful as a sealant film for a packaging film.

(2) Anti-fogging property in a low temperature environment 100 mL of distilled water at 23 ° C. is placed in a polypropylene cylindrical container having a bottom diameter of 50 mm and a depth of 80 mm, and then a sealant layer is directed to the container side using a film. The container was packaged so that the opening of the container was hermetically sealed, stored in a thermostatic chamber at a set temperature of 3 ° C. for 24 hours, and the degree of cloudiness of the film after storage was evaluated according to the following criteria.
In addition, the multilayer film of Examples 11-20 evaluated also about the film before winding up in roll shape.
A: The contents can be clearly seen without moisture condensing on the film surface.
○: Water condenses on the film surface, but the water film becomes uniform and the contents can be visually recognized.
Δ: Moisture condenses on the film surface, the water film becomes non-uniform lens shape, and the contents are difficult to visually recognize.
X: Water becomes fine water droplets on the film surface, and the contents cannot be visually recognized.

(3) Anti-fogging property under high-temperature steam 100 mL of hot water of 90-95 ° C. is put into a polypropylene cylindrical container having a bottom diameter of 50 mm and a depth of 80 mm, and then a sealant layer is placed on the container side using a film. The container was packaged so that the opening of the container was sealed, and the degree of fogging after 10 seconds was evaluated according to the following criteria as the initial antifogging property under high-temperature steam.
In addition, the multilayer film of Examples 11-20 evaluated also about the film before winding up in roll shape.
A: The contents can be clearly seen without moisture condensing on the film surface.
○: Water condenses on the film surface, but the water film becomes uniform and the contents can be visually recognized.
Δ: Moisture condenses on the film surface, the water film becomes non-uniform lens shape, and the contents are difficult to visually recognize.
X: Water becomes fine water droplets on the film surface, and the contents cannot be visually recognized.

(4) Wettability The film is left to stand horizontally, distilled water is dropped on the surface of the sealant layer in an atmosphere of 23 ° C., and the contact angle (degree) between the surface of the sealant layer and distilled water 20 seconds after the dropping. Was measured.
The smaller the value of the contact angle, the better the anti-fogging property at room temperature.

(5) Sliding property In a 23 ° C atmosphere, the sliding property when the film was manually slid in the horizontal direction with a contact area of 50 mm square on a biaxially stretched PET film with a thickness of 12 μm that was placed horizontally was as follows. Evaluation based on the criteria.
A: It slides very well.
○: Glide without resistance.
Δ: There is some resistance, but it slides.
X: The film sticks and does not slip at all.

(6) Total haze Under an atmosphere of 23 ° C., the total haze (%) of the film at a thickness of 20 μm was measured in accordance with JIS K7136 to evaluate transparency.

The films of Examples 1 to 18 and Comparative Examples 1 to 7 all had a heat seal strength of 3 N / 15 mm width or more, and had a sufficient sealant function.
Examples 1 to 10 showed good antifogging properties under low temperature environment and high temperature steam, and also had good slipping and transparency.
Comparative Examples 1 and 6 had good antifogging properties and transparency under a low temperature environment and high temperature steam, but did not contain the antifogging agent (a) in the sealant layer, and the slipperiness was poor.
In Comparative Example 2, the content of the antifogging agent (a) was high, and the antifogging property under a low temperature environment was insufficient.
Comparative Example 3 did not contain the antifogging agent (b) and had poor transparency.
In Comparative Example 4, the content ratio of the antifogging agent (a) was high, the antifogging agent (b) was not contained, the antifogging property under a low temperature environment was insufficient, and the total haze value was also high.
Comparative Example 5 did not contain the antifogging agent (c), and Comparative Example 7 had a low HLB value of the antifogging agent (c), and the antifogging property was insufficient.

In Examples 11 to 15 and 18, the surface layer on the side opposite to the sealant layer is made of a polyolefin resin or a polyester resin, and has good antifogging property under low temperature environment and high temperature steam, and before and after winding the roll. showed that. Moreover, the slipperiness was also good and the total haze was 10% or less.
In Examples 16 and 17 in which the surface layer opposite to the sealant layer is made of nylon 6 resin, the film before roll winding has good anti-fogging property under both low temperature environment and high temperature steam, and roll winding. The film after predetermined standing was insufficient in antifogging property.

The film for sealant of the present invention is excellent in antifogging property in a wide temperature range at low temperature, normal temperature and high temperature in addition to heat sealability, and also has excellent transparency and slipperiness. It can be used suitably.
In particular, because it is difficult to block due to its good slipperiness, web handling troubles in secondary processing processes such as slitting, printing, and bag making are unlikely to occur, and because of its good anti-fogging property, packaging of food contents containing moisture Even when refrigerated and heated for cooking, high contents visibility is obtained, which is highly useful.

Claims (9)

A film comprising an unstretched layer (S layer) containing an ethylene polymer and an antifogging agent (A), (B), and (C), or an ethylene polymer and an antifogging agent (A), (B And an unstretched layer (S layer) containing (C) as at least one surface layer,
The ethylene polymer has a melting point of 60 ° C. or higher and 130 ° C. or lower,
The antifogging agent (A) is a glycerin saturated fatty acid ester having a melting point of 40 ° C. or higher,
Anti-fogging agent (B) is a glycerin fatty acid ester that is liquid at a temperature of less than 40 ° C.,
The antifogging agent (C) is an ethylene oxide adduct having a lipophilic hydrophilic balance (HLB) of 9.0 or more, and
A film, wherein the mass ratio of the antifogging agent (A) to the total mass of the antifogging agents (A), (B), and (C) is 5% or more and less than 60%.   The ethylene polymer is one or a mixture of two or more selected from low density polyethylene, ethylene-vinyl acetate copolymer, and ethylene- (meth) acrylic acid ester copolymer. Film.   The film according to claim 1 or 2, wherein the antifogging agent (A) is a monoester or diester obtained from a combination of glycerin and a saturated fatty acid having 12 to 20 carbon atoms.   The antifogging agent (B) comprises a monoester or diester of glycerin and a saturated or unsaturated fatty acid having 12 to 20 carbon atoms, and has a lipophilic hydrophilic balance (HLB) of 4 to 8. 4. The film according to any one of 3.   The film according to claim 1, further comprising a gas barrier layer.   The film according to claim 1, wherein the other surface layer of the film is a polyester resin layer or a polyolefin resin layer.   The film according to any one of claims 1 to 6, which is used for a sealant.   When the film is unwound from a film roll obtained by winding the film into a roll, the mass ratio of the total mass of the antifogging agents (A), (B), and (C) to the total mass of the S layer is 1 It is 0.0% or more and 8.0% or less, The film in any one of Claims 1-7.   A package comprising the film according to claim 1.