JP2015066801A - Non-adsorbent sealant film and laminate for packaging material composed of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealant film which exhibits excellent non-adsorptive properties and seal strength and is easily formed.SOLUTION: There is provided a non-adsorbent sealant film which is composed of at least a base resin layer and a seal layer, wherein the seal layer is composed of an amorphous copolyester having a glass transition point of 70 to 90°C and is laminated on the base resin layer by extrusion coating.

Description

  The present invention relates to a non-adsorptive sealant film in which the amount of adsorption of active ingredients contained in the contents of chemical products, pharmaceuticals, foods, etc. is reduced, and a laminate for packaging materials comprising the same, and more specifically, the contents The present invention relates to a sealant film capable of maintaining a high content of an active ingredient in a product, exhibiting high sealing strength, and easily forming a film, and a laminate for a packaging material comprising the same.

  Conventionally, the innermost layer of a packaging material such as a packaging bag or a lid material is provided with a sealant layer made of a polyolefin resin such as polyethylene or polypropylene showing high sealing strength, or a copolymer resin such as ionomer or EMMA. These resins can achieve high adhesion strength by heat sealing, but are known to easily adsorb various organic compounds. Therefore, a packaging material having a sealant layer made of these resins as the innermost layer, that is, a layer in contact with the contents, is not suitable for packaging chemical products, pharmaceuticals, foods, etc. containing an organic compound as an active ingredient. It is necessary to take measures such as adding more active ingredients.

Accordingly, development of a sealant layer that has a good seal strength and hardly adsorbs active ingredients has been made. Typically, a packaging material having a non-adsorptive sealant layer made of acrylonitrile resin as the innermost layer is used (Patent Document 1).
However, since an acrylonitrile-based resin does not provide good sealing strength and is expensive, development of a more preferable non-adsorptive sealant film is required.

  On the other hand, for example, Patent Document 2 discloses a non-adsorbing packaging material in which the innermost layer is formed of an aluminum foil or an inorganic vapor-deposited film. The packaging material is used by making a bag by partially forming an adhesive resin layer on the aluminum foil or vapor deposition film. As the adhesive resin layer, urethane resin, vinyl chloride-vinyl acetate copolymer, acrylic resin, and the like are disclosed. However, such a packaging material has a complicated manufacturing process.

JP-A-7-132946 Japanese Patent Laid-Open No. 10-45176

  An object of the present invention is to solve the above-described problems, to provide a sealant film that exhibits excellent non-adsorption properties and seal strength, and that can be easily formed, and a laminate for packaging material comprising the same. To do.

  As a result of various studies, the inventor has found that the non-adsorptive sealant film includes at least a base resin layer and a seal layer, and the seal layer has an amorphous property having a glass transition point of 70 to 90 ° C. It has been found that the non-adsorptive sealant film, which is made of a copolyester and is laminated on the base resin layer by extrusion coating, achieves the above-described object.

The present invention is characterized by the following points.
(1) A non-adsorptive sealant film comprising at least a base resin layer and a seal layer, the seal layer comprising an amorphous copolyester having a glass transition point of 70 to 90 ° C., The non-adsorptive sealant film, which is a layer laminated on the base resin layer by extrusion coating.
(2) The non-adsorptive sealant film according to (1) above, wherein an easy adhesion treatment is performed on the laminated surface of the base resin layer.
(3) Before the extrusion coating of the seal layer onto the base resin layer, an anchor coating agent is applied to the laminated surface of the base resin layer, as described in (1) or (2) above Non-adsorptive sealant film.
(4) A laminate for packaging material, comprising at least a base film layer and a layer comprising the non-adsorptive sealant film according to any one of (1) to (3) above.

  A generally known single-layer sealant film made of only a polyolefin resin has a thickness proportional to an organic compound adsorption amount and a sealing strength. Therefore, when the sealant film of the packaging bag is thinned to prevent the contents from being adsorbed, the sealing strength is lowered and the impact resistance of the bag is lowered. Further, when the sealant film is thickened to improve the impact resistance, the amount of content adsorbed increases.

  On the other hand, the non-adsorptive sealant film of the present invention exhibits both excellent non-adsorptive properties and seal strength by extruding an amorphous copolymer polyester having a glass transition point of 70 to 90 ° C. To achieve.

Moreover, this tendency becomes more remarkable by laminating by extrusion coating on a base resin layer made of a resin film. That is, it has been found that a high interlayer adhesion strength can be obtained and the non-adsorption property and the sealing strength can be increased by backing the sealing layer made of the copolyester with a base resin layer made of a resin film.
In addition, before laminating a sealing layer made of a copolyester on a base resin layer made of a resin film, by applying an anchor coating agent to the laminated surface of the base resin layer, the interlayer adhesive strength is increased and non-adsorption And seal strength were further improved.

The non-adsorptive sealant film of the present invention is difficult to adsorb various organic compounds, particularly fat-soluble substances such as l-menthol, camphor (camphor), isopropylmethylphenol (IPMP), vitamin E acetate and limonene. These can be used suitably as packaging materials.
Furthermore, the laminate having the non-adsorbable sealant film of the present invention as a sealant layer is suitable for use as various packaging materials, and in particular, in order to form a pharmaceutical packaging bag that requires non-adsorbability, It can be preferably used.

It is a schematic sectional drawing which shows an example about the layer structure of the non-adsorptive sealant film of this invention. It is a schematic sectional drawing which shows another example about the layer structure of the non-adsorptive sealant film of this invention. It is a schematic sectional drawing which shows an example about the layer structure of the laminated body which has a non-adsorptive sealant film of this invention. It is a schematic sectional drawing which shows another example about the layer structure of the laminated body which has a non-adsorptive sealant film of this invention.

The above-described present invention will be described in more detail below.
<1> Layer structure of non-adsorptive sealant film of the present invention and laminate having the same FIGS. 1 to 4 are schematic cross sections showing an example of the layer structure of the non-adsorptive sealant film of the present invention and the laminate having the same. FIG.
As shown in FIG. 1, the non-adsorptive sealant film of the present invention is basically composed of two layers, a base resin layer 1 and a seal layer 2.
Moreover, as shown in FIG. 2, before laminating | stacking a sealing layer on the base resin layer 1, you may provide the arbitrary easily bonding layers 3 in the lamination | stacking surface. In some cases, the anchor coating agent layer 4 may be provided on the surface of the easy-adhesion layer 3.

Furthermore, as a laminated body which has the non-adsorptive sealant film of this invention, as shown in FIG. 3, the laminated body which has the non-adsorptive sealant film A of this invention and the base film B can be mentioned. In this laminate, the sealing layer 2 forms the outermost layer, that is, the innermost layer when applied to a package. The non-adsorptive sealant film A and the base film B may be laminated by laminating via the adhesive layer C. Moreover, the base film B may have arbitrary structures according to a packaging use.
As a specific aspect of the base film B, as shown in FIG. 4, the aspect which consists of the resin film 5, the adhesive bond layer 6, and the aluminum foil 7 can be mentioned as an example.
Hereinafter, the resin names used in the present invention are those commonly used in the industry.

<2> Base resin layer The base resin layer of the non-adsorptive sealant film of the present invention is made of an arbitrary resin film. Any resin film used for various packaging materials and packaging containers can be used, and a suitable one can be freely selected and used according to the type of base film to be bonded.
Specific examples of the resin film constituting the base resin layer include olefin resins (polyethylene resins, polypropylene resins, etc.), halogen-containing resins (vinyl chloride resins, etc.), vinyl alcohol resins, (meth) acrylic resins. Examples thereof include resin films made of styrene resin, polyamide resin (polyamide 6, polyamide 66, etc.), polycarbonate resin, polysulfone resin (polyether sulfone, polysulfone, etc.), polyphenylene ether resin, and the like. The resin film may be unstretched or a uniaxial or biaxially stretched film. Moreover, the resin film of the multilayer structure which bonded together the 2 or more resin film may be sufficient.
In addition, the laminated surface of the resin film constituting the base resin layer, that is, the surface on which the adhesive resin layer is laminated is an easily adhesive layer (for example, a corona discharge treatment layer) by surface treatment in order to improve adhesion to the adhesive resin layer. , A primer treatment layer, etc.) may be provided.

<3> Seal layer The seal layer of the non-adsorptive sealant film of the present invention is made of an amorphous copolyester having a glass transition point of 70 to 90 ° C, more preferably 70 to 80 ° C.
A typical example of the copolyester in the present invention is copolyethylene terephthalate (PET). As such a copolymerized PET, terephthalic acid and ethylene glycol are the main components, and a polyvalent carboxylic acid other than terephthalic acid and / or a polyhydric alcohol other than ethylene glycol is used as the copolymer component. A modified PET obtained by adding and copolymerizing such that the glass transition point is 70 to 90 ° C. is used.

  In the present invention, the term “amorphous” means that there is no melting peak when the temperature is raised from −100 ° C. to 300 ° C. at a rate of 20 ° C./min using a differential scanning calorimeter (DSC). To do.

In the present invention, the glass transition point is measured in accordance with JIS K7121.
As polyvalent carboxylic acids added as copolymerization components, isophthalic acid, orthophthalic acid, adipic acid, azelaic acid, sebacic acid, dimer acid (mainly dimers of unsaturated fatty acids or their hydrogenated products) , Diphenylcarboxylic acid, trimellitic acid, pyromellitic acid, sodium 5-sulfoisophthalate and the like.
Examples of the polyhydric alcohol added as a copolymerization component include diethylene glycol, propylene glycol, 1,4-cyclohexanedimethanol, trimethylolpropane, neopentyl glycol, 1,4-butanediol, 1,5-pentanediol, Examples include 1,6-hexanediol, pentaerythritol, bisphenol A ethylene oxide adduct, and the like.

Specific examples of the copolymerized PET include a co-condensation polymer of a combination of terephthalic acid, isophthalic acid and ethylene glycol, terephthalic acid and ethylene glycol and 1,4-cyclohexanedimethanol, terephthalic acid, isophthalic acid and propylene glycol, and the like. PET which becomes is mentioned.
The mixing ratio of the main component and the copolymer component is not particularly limited as long as it exhibits amorphous properties and has a desired glass transition point. For example, 50 mol% or more of the polyvalent carboxylic acid used as a raw material is terephthalic acid. Moreover, 50 mol% or more of the polyhydric alcohol used as a raw material is ethylene glycol. If the amount of terephthalic acid and ethylene glycol as raw materials is less than this, impact resistance and non-adsorption properties can be impaired.

Further, the total amount of terephthalic acid and ethylene glycol as main components is 50 to 95 mol% with respect to 100 mol% of the total amount of polyvalent carboxylic acid and polyhydric alcohol as raw materials, and the total of copolymer components The amount is preferably 5 to 50 mol%. When the total amount of the copolymerization components is less than 5 mol%, the amorphous property is lost and the seal strength is impaired.
Furthermore, in this invention, the copolymer polyester prepared so that a glass transition point may become 70-90 degreeC among the said amorphous copolyester is used. This preparation can be appropriately performed by those skilled in the art by changing the mixing ratio, degree of polymerization, and the like according to the chemical structure of the polyvalent carboxylic acid and polyhydric alcohol used as raw materials.

  In the present invention, by using an amorphous polyester having a glass transition point of 70 to 90 ° C., excellent seal strength and heat sealability can be obtained by heat sealing at 100 to 200 ° C., more preferably 120 to 160 ° C. Demonstrated. If the glass transition point is outside this range, the low-temperature sealability is impaired, or sufficient seal strength cannot be obtained, which is not preferable.

An amorphous copolyester satisfying the above requirements and having a glass transition point of 70 to 90 ° C. is also commercially available. As a material suitably used in the present invention, Byron ^(R) (Toyobo ⁾ Co., Ltd.) and Eastar PETG (manufactured by EASTMAN CHEMICAL Co., Ltd.).

  Here, the seal layer may contain an antiblocking agent in an amount of 1 to 10% by mass, more preferably in an amount of 3 to 5% by mass. By including the antiblocking agent in this amount, the slipperiness of the film can be improved without impairing the sealing strength, non-adsorption property, and interlayer adhesion strength with the base resin layer.

Anti-blocking agents preferably used in the present invention include oxides such as aluminum oxide, magnesium oxide, silica, calcium oxide, titanium oxide, and zinc oxide, and hydroxides such as aluminum hydroxide, magnesium hydroxide, and calcium hydroxide. Carbonates such as magnesium carbonate and calcium carbonate, sulfates such as calcium sulfate and barium sulfate, silicates such as magnesium silicate, aluminum silicate, calcium silicate and aluminosilicate, and others, kaolin, talc and diatomaceous earth And inorganic compound-based antiblocking agents, and mixtures of two or more thereof.

  Further, the seal layer may further comprise an antioxidant, an ultraviolet absorber, a light stabilizer, an antistatic agent, a lubricant (fatty acid amide, etc.), a flame retardant, an inorganic material, as long as it does not impair the effects of the present invention. It may also contain one or more additives such as organic fillers, crosslinking agents, colorants such as dyes and pigments, and additives such as modifying resins.

<4> Production of non-adsorptive sealant film The non-adsorptive sealant film of the present invention is produced by extrusion coating the above-mentioned copolymer polyester forming a seal layer on a resin film forming a base resin layer.
The extrusion temperature can be appropriately selected by those skilled in the art depending on the type of copolymer polyester, and may be in a wide temperature range of, for example, 200 to 280 ° C.
By extruding the copolymerized polyester on a resin film, high non-adsorption property and sealing strength are exhibited.

Here, the layer thickness of the base resin layer is 10 to 30 μm, more preferably 10 to 20 μm. If it is thinner than 10 μm, the strength as a substrate is insufficient, and if it is thicker than 30 μm, it is hard as a sealant film, and the cost is not preferred.
The layer thickness of the seal layer is 15 to 60 μm, more preferably 20 to 50 μm. If it is thinner than 15 μm, the stability is poor and the sealing strength is weak, and if it is thicker than 60 μm, it is hard as a sealant film and the cost is not preferred.

Before the seal layer is extrusion coated on the base resin layer, the laminated surface of the base resin layer may be surface-treated.
In particular, by applying a polyurethane-based, polyester-based, or acrylic-based anchor coat agent to the laminated surface of the resin film constituting the base resin layer, and in some cases, by further ozone treatment, adhesion between the layers can be further increased. improves.

<5> Laminate A laminate for a packaging material can be obtained by laminating a base film layer on a layer made of the sealant film of the present invention.
As the base film layer used here, a single-layer film such as a plastic film or a multilayer laminated film is used, but is not particularly limited, and any film used for various packaging bags and packaging containers can be used. . Among these, a suitable one is freely selected and used according to the use conditions such as the type of contents to be packaged and the presence or absence of heat treatment after filling. As a specific example of a laminate preferably used, on a biaxially stretched PET film, a multilayer laminated film in which an aluminum foil is bonded via an adhesive layer as a base film, on the surface of the aluminum foil side, The non-adsorptive sealant film of the present invention may be laminated such that the seal layer is the outermost layer, and laminated by dry lamination or the like.

<6> Packaging Bag Using the above laminate, a bag can be formed by forming a bag so that the layer made of the non-adsorbing sealant film becomes the innermost layer. Moreover, a packaging container can be manufactured using the said laminated body as a cover material which makes a nonadsorbable sealant film layer the innermost layer.

In order to produce a packaging bag, the laminate is folded in two or two laminates are prepared, and the non-adsorbing sealant film layer faces are overlapped, and the peripheral edge is, for example, Standing pouch type, side seal type, two-side seal type, three-side seal type, four-side seal type, envelope-attached seal type, joint-attached seal type (pillow seal type), pleated seal type, flat bottom seal type, square bottom seal type Then, heat sealing is performed by a heat sealing form such as a gusset type to form packaging bags of various forms.

In the above, as a heat sealing method, for example, a known method such as a bar seal, a rotary roll seal, a belt seal, an impulse seal, a high frequency seal, and an ultrasonic seal can be used.
To manufacture a packaging container using the laminate as a lid, the laminate is overlaid so that the surface of the non-adsorptive sealant film layer is in contact with the opening of the resin container, and heat-sealed in the same manner as the bag. Can be done.
Packaging bags and packaging containers made of the above laminate are particularly suitable for packaging chemical products, pharmaceuticals, quasi drugs, cosmetics, foods, etc. containing organic compounds as active ingredients. Or it can use suitably as a standing pouch used for the contents for refilling, such as lotion.
Next, the present invention will be specifically described with reference to examples.

[Example 1]
(1) A biaxially stretched nylon film (Konjin Film & Chemicals Co., Ltd. Bonil Q; thickness 15 μm) is prepared as a base resin layer, and a polyurethane anchor coating agent (Mitsui Chemicals, Inc.) is provided on one surface thereof. Takelac / Takenate, A-3210 / A-3075; blending ratio 3/1) was applied at a coating amount of 0.4 g / m ² using a diagonal plate with a plate depth of 20 μm.
(2) Next, an amorphous PET (SI-173 manufactured by Toyobo Co., Ltd .; glass transition point 78 ° C.) was laminated as a seal layer on the anchor coating agent-coated surface by extrusion coating so as to have a layer thickness of 30 μm. A non-adsorptive sealant film of the present invention having a layer structure of base resin layer / anchor coating agent layer / seal layer was produced.
(3) On the other hand, a biaxially stretched PET film (E5100 manufactured by Toyobo Co., Ltd .; thickness 12 μm) was used, and an adhesive (Rock Bond J / Adlock manufactured by Rock Paint Co., Ltd., RU77T / H) was formed on one surface thereof. -7; compounding ratio 10/1) was applied at a coating amount of 3.0 g / m ² using a diagonal plate with a plate depth of 90 μm, and an aluminum foil having a thickness of 7 μm (A1N30H-O manufactured by Nippon Foil Co., Ltd.) ) And stored in a constant temperature bath at 40 ° C. for 48 hours, and the adhesive was cured to obtain a base film. (4) An adhesive is similarly applied to the surface of the base film provided with the aluminum foil, and the sealant film of the present invention produced in (2) is bonded so that the seal layer is the outermost layer. The laminate was manufactured by storing for 48 hours in a thermostat at 0 ° C. and curing the adhesive. The layer structure of the resulting laminate was as follows:
Base film layer (PET film / adhesive layer / aluminum foil) / adhesive layer / base resin layer / anchor coat agent layer / seal layer

[Comparative Example 1]
A sealant film and a laminate are produced in the same manner as in Example 1 except that a low density polyethylene resin (LDPE; Novatec LC522 manufactured by Nippon Polyethylene Co., Ltd.) is used instead of amorphous PET in the formation of the sealing layer. did.

[Comparative Example 2]
In the formation of the seal layer, a sealant film and a laminate were formed in the same manner as in Example 1 except that a linear low density polyethylene resin (LLDPE; Sumikasen CW8003 manufactured by Sumitomo Chemical Co., Ltd.) was used instead of amorphous PET. The body was manufactured.

[Evaluation methods and results]
(1) Adsorption test (1-menthol)
The sealant films of Examples and Comparative Examples were cut into 10 cm × 10 cm squares, and their initial weights were measured.
Put 10 g of l-menthol solid (Pure Chemical Co., Ltd.) in a stainless steel container with a capacity of 10 liters, cover the container with l-menthol vapor, and suspend the cut sealant film in it. Stored at 7 ° C. for 7 days.
After storage, the sealant film was taken out and weighed, and the amount of l-menthol adsorbed was calculated from the difference from the initial weight.

(2) Adsorbability test (dl-α-tocopherol acetate)
The sealant films of Examples and Comparative Examples were cut into 5 cm × 5 cm squares and their initial weights were measured.
A dl-α-tocopherol acetate solution (Kanto Chemical Co., Ltd.) was applied to the surface on the seal layer side, closely adhered to a glass petri dish with the coated surface facing down, covered, and stored at 40 ° C. for 7 days.
After storage, the sealant film was taken out, the dl-α-tocopherol solution on the coated surface was removed, the weight was measured, and the adsorption amount of dl-α-tocopherol acetate was calculated from the difference from the initial weight.

(3) Seal strength test The sealant films of Examples and Comparative Examples were overlapped with the base resin layer facing outside, and heat sealer (TP-701S HEAT SEAL TESTER manufactured by Tester Sangyo Co., Ltd.) at 160 ° C for 1 second. Heat sealing was performed at a pressure of 1 kgf / cm ² .
Next, this was cut out into a strip shape having a width of 15 mm, and the sealed portion was peeled off using a Tensilon tensile tester (RTC-1310A manufactured by Orientec Co., Ltd.), and the seal strength was measured. The tensile speed at this time was 300 mm / min.
The results are shown in the following table.

  The sealant film of Example 1 exhibited high non-adsorbability and seal strength. In contrast, the laminates of Comparative Examples 1 and 2 adsorbed a large amount of l-menthol and dl-α-tocopherol acetate although high sealing strength was exhibited.

A. Non-adsorptive sealant film Base film C.I. Adhesive layer Base resin layer2. 2. Seal layer 3. Easy adhesion layer 4. Anchor coat agent layer Resin film 6. Adhesive layer Aluminum foil

Claims (4)

A non-adsorptive sealant film comprising at least a base resin layer and a seal layer,
The non-adsorptive layer, wherein the seal layer is made of an amorphous copolyester having a glass transition point of 70 to 90 ° C and is laminated on the base resin layer by extrusion coating. Sealant film.   The non-adsorptive sealant film according to claim 1, wherein an easy adhesion treatment is performed on a laminated surface of the base resin layer.   The non-adsorptive sealant film according to claim 1 or 2, wherein an anchor coat agent is applied to the laminated surface of the base resin layer before the sealing layer is extrusion coated onto the base resin layer.   The laminated body for packaging materials which consists of a base film layer and the layer which consists of a non-adsorptive sealant film of any one of Claims 1-3 at least.

Images