JPH09327883A - Intensively adhesive transparent laminate having gas barrier properties - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent laminate strength from being deteriorated even though an attach of contents are provided with aging while easily adhesive properties are given to a plastic film by a method wherein a first layer of a transparent primer layer is made of a mixed series of a polyester resin and an isocyanate resin, and a second layer is made of a melamine resin. SOLUTION: As a primer, a mixture of a polyester resin and an isocyanate resin is provided. Then, a first layer 12 of the primary is provided on a plastic base material 11, adhesion in the case of providing a barrier film layer comprising an inorganic compound on the primer layer is raised, and deterioration of aged laminate strength after filling contents is prevented. Then, as the primer 13, a melamine resin is provided. The second layer 13 of the transparent primer is provided on the first layer 12 of the transparent primer layer, excellent in surface smoothness, and excellent barrier properties are developed when the barrier film layer 14 comprising an inorganic compound is provided on the second layer 13 of the primer layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminate for packaging used in the field of packaging foods, medicines and the like.

[0002]

2. Description of the Related Art In the field of packaging materials, laminates such as sealant films having heat sealing properties are known.
As a method of laminating these, a method of laminating via an adhesive, a method of laminating via a hot-melted resin layer, and an extrusion (hereinafter abbreviated as EXT) laminating are generally used. Since the stronger the adhesive strength, the better,
The base film and the sealant film are often subjected to an easy adhesion treatment. Easy adhesion treatment method is chemical surface treatment,
Although there is a method such as gas flame treatment, corona treatment is generally used for controllability and uniformity of treatment. In addition, when extruding a non-polar resin such as polyethylene in the EXT laminate, the adhesive strength is insufficient even with a corona-treated substrate. is there. In any of the methods, it is the current situation that the laminate strength often deteriorates with time depending on the contents to be filled. In particular, when a thin film layer made of an inorganic compound such as aluminum oxide, magnesium oxide, tin oxide, or silicon oxide is laminated for the purpose of imparting a gas or water vapor barrier property to the packaging material, the plastic film surface and the inorganic compound are combined. The adhesion between the thin film layers is weak, and peeling frequently occurs from there.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it imparts easy adhesiveness to a plastic film of a base material or a sealant, and the contents may be attacked over time. At the same time, the so-called content resistance that the laminate strength does not deteriorate is given,
Moreover, the object is to provide a transparent laminate having a high barrier property.

[0004]

The present invention is to achieve this object, and the invention of claim 1 comprises two different transparent primer layers and an inorganic compound on a substrate made of a transparent plastic material. In a structure in which barrier thin film layers are sequentially laminated, the first layer of the transparent primer layer is a layer composed of a mixed system of polyester resin and isocyanate resin,
The second layer is a layer made of a melamine resin, which is a strong adhesion transparent laminate having a gas barrier property. Also, the invention of claim 2 is characterized in that the barrier thin film layer made of the inorganic compound is aluminum oxide, magnesium oxide, tin oxide, silicon oxide, or a mixture thereof, It is a strong adhesion transparent laminated body which has.

The laminate of the present invention has a barrier property made of an inorganic compound by sequentially providing a layer made of a mixed system of a polyester resin and an isocyanate resin and a layer made of a melamine resin on a substrate made of a transparent plastic material. Improves the adhesiveness when laminating the thin film layers, and further can prevent the deterioration of the laminate strength with the time of filling the adhesiveness and the contents when laminating a film or resin layer having heat sealing property, It also has a high gas barrier property.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the drawings. Drawing 1 is a sectional view of a transparent layered product of the present invention.

The laminated body of FIG. 1 will be described. The base material 11 in FIG. 1 is a film made of a transparent plastic material, and includes a primer layer first layer 12 and a primer layer second layer 1.
3. The gas barrier thin film layer 14 made of an inorganic compound is sequentially laminated.

The substrate 11 made of a transparent plastic material used in the present invention is used as a usual packaging material for polyolefin, polyester, polyamide, polyvinyl chloride, polyimide or the like, or a copolymer of these polymers. It is what is done. In general, a biaxially stretched polyethylene terephthalate film is preferably used because of its transparency and thermal stability.

The substrate 11 and the primer layers 12, 1 of the present invention
If 3 is transparent, the effect is further enhanced, but semi-transparent even if it is not completely transparent, and colored transparent or opaque is also effective.

The thickness of the plastic film is 3 to 2
In the range of 00 μm, a thickness of 6 to 100 μm is desirable.
In addition, there is no problem in including additives and stabilizers (antistatic agent, ultraviolet absorber, plasticizer, lubricant, etc.). Further, there is no problem even if the film is subjected to surface treatment (corona treatment, plasma treatment, etc.).

The first layer 1 of the transparent primer according to the present invention
2 is provided on the plastic substrate 11 and enhances the adhesiveness when a barrier thin film layer made of an inorganic compound is provided on the primer layer, and a film having heat sealability on the barrier thin film layer, or The purpose of the present invention is to improve the adhesiveness when the resin layers are laminated and prevent the deterioration of the laminate strength over time after filling the contents.

It is necessary that a mixture of a polyester resin and an isocyanate resin can be used as a primer used for achieving the above object.

The polyester resin used as the first layer 12 of the primer layer is terephthalic acid, isophthalic acid, phthalic acid, methylphthalic acid, trimellitic acid, pyromellitic acid, adipic acid, sebacic acid, succinic acid, maleic acid,
Acid raw materials such as fumaric acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, hexahydrophthalic acid and their reactive derivatives, and ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 1, 6-hexanediol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanedimethanol, neopentyl glycol, isopentyl glycol, bishydroxyethyl terephthalate, hydrogenated bisphenol A, alkylene oxide adduct of hydrogenated bisphenol AA, trimethylolethane ,
It is produced by a known method from an alcohol raw material such as trimethylolpropane, glycerin, pentaerythritol, and 2,2,4-trimethylpentane-1,3-diol, and is not particularly limited.

As the isocyanate resin used as the first layer 12 of the primer layer, aromatic tolylene diisocyanate (TDI), 4,4'diphenylmethane diisocyanate (MDI), aliphatic hexamethylene diisocyanate (HMDI), and isophorone diisocyanate are used. (IPDI), xylylene diisocyanate (XD
I) and the like are mentioned, but not particularly limited, but among them, TDI type is preferable.

A known method can be used as a method for mixing the polyester resin and the isocyanate resin, and there is no particular limitation.

The mixing ratio of the polyester resin and the isocyanate resin is not particularly limited, but if the isocyanate resin is too little or too much, the primer layer 1 may cause curing failure, so the mixing ratio is ( OH group of polyester): (NCO group of isocyanate)
Therefore, 1: 0.5 to 1:20 is preferable.

Second layer 1 of transparent primer according to the present invention
3 is provided on the transparent primer layer first layer 12. This primer layer second layer 13 has excellent surface smoothness, and is intended to exhibit excellent barrier properties when the barrier thin film layer 14 made of an inorganic compound is provided on the primer layer second layer 13.

It is necessary that a melamine resin can be used as the primer 13 used to achieve the above object.

The melamine resin used as the second layer 13 of the primer is not particularly limited and may be a commercially available product.

Further, by providing the second layer 13 of the transparent primer, the effect of reducing the residual solvent can be seen at the same time.

Additives other than the above, such as tertiary amine, imidazole derivative, metal salt compound of carboxylic acid, quaternary ammonium salt, and quaternary borophonium salt are added to the first and second primer layers 12 and 13 of the present invention. Hardening accelerators such as, phenol-based, sulfur-based, phosphite-based antioxidants,
A leveling agent, a flow control agent, a catalyst, a crosslinking reaction accelerator, a filler and the like can also be added.

The resin used for the primer can be dissolved by a usual method and is not particularly limited.

The thickness of the first layer 12 and the second layer 13 of the primer layer is not limited, but is generally 1 nm or less to 1000 nm.
Is desirable. A well-known method can be used as a method for forming the primer layer. For example, a gravure coat or the like. Also, the drying method is not particularly limited, and a normal method can be used.

The thin film layer made of the inorganic compound according to the present invention is provided for the purpose of improving the barrier property of the base material, and for example, oxides, nitrides and fluorides of Al, Si, Sn, Mg and the like. And the like, or a mixture thereof. Among them, aluminum oxide, magnesium oxide, tin oxide and silicon oxide are particularly excellent in gas barrier property. However, the inorganic compound thin film layer of the present invention is not limited to the above compounds, and any material that meets the above conditions can be used.

The thickness of the inorganic compound layer depends on the application and the thickness of the base plastic film, but if the thickness is 5 nm or less, it is difficult to control the thickness uniformly. If the thickness is 300 nm or more, cracks are likely to occur, and the kneading property is reduced.

The inorganic compound layer can be formed by a usual method such as a dry coating method. For example, a vacuum vapor deposition method, a sputtering method, an ion plating method, or the like. However, in consideration of productivity, vacuum evaporation is currently the best. As a heating means of the vacuum evaporation apparatus by the vacuum evaporation method, an electron beam heating method, a resistance heating method, and an induction heating method can be used.

Another substrate (plastic film, paper, etc.) or a heat-sealable resin may be laminated on the laminate having this structure. A well-known method (dry laminating, EXT laminating, etc.) can be used for the laminating method, and there is no particular limitation.

A printing layer may be provided on the inorganic compound layer of the laminate having this structure. The ink used in the printing layer is a urethane-based, acrylic-based, nitrocellulose-based, rubber-based, vinyl chloride-based binder resin with a pigment, plasticizer,
A mixture of a desiccant and a stabilizer is generally used. The present invention is not particularly limited to ink. The printing method includes an offset method, a gravure method, and a silk screen method, and is not particularly limited.

[0029]

EXAMPLES The laminate of the present invention will be described in more detail with reference to Examples.

<Preparation of First Layer Primer> First layer primer 1 was mixed in the following mixing ratio. First layer primer 1A: Polyester resin and isocyanate resin were mixed such that (OH group of polyester resin) :( NCO group of isocyanate group) was 1: 4. First layer primer 1B: Polyester resin and isocyanate resin were mixed such that (OH group of polyester resin) :( NCO group of isocyanate group) was 1:16. First layer primer 1C: Polyester resin and isocyanate resin were mixed such that (OH group of polyester resin) :( NCO group of isocyanate group) was 1:32. Toluene: methyl ethyl ketone = 1:
It was diluted with a mixed solvent mixed in a weight ratio of 1 so that NV (solid content) was 5%.

<Preparation of Second Layer Primer> Second layer primer 2A; melamine resin having a solid content of 4
%. Second layer primer 2B; melamine resin having a solid content of 15
%. Toluene was used as the solvent. Further, 0.003% of antimony chloride was added to these solutions as a curing accelerator.

<Example 1> Primer 1A was applied to one side of a biaxially stretched polyethylene terephthalate film (12 μm).
And primer 2A are sequentially laminated by coating and 1
A laminate in which a second layer of a 80 nm primer layer is laminated on a first layer primer of 00 nm is obtained. Further, vacuum deposition is performed by an electron beam heating method to deposit silicon oxide at 40 to 50 nm.
To obtain the laminate of the present invention.

Example 2 Primer 1A was applied to one side of a biaxially stretched polyethylene terephthalate film (12 μm).
And primer 2B are sequentially laminated by coating, and 1
A laminated body in which a 500 nm-thick primer layer second layer is laminated on a 00-nm primer layer first layer is obtained. Further, vacuum evaporation is performed by an electron beam heating method to add 40 to 50 silicon oxide.
The layers were laminated so as to have a thickness of nm to obtain a layered product of the present invention.

Example 3 Primer 1B was formed on one side of a biaxially stretched polyethylene terephthalate film (12 μm).
And primer 2A are sequentially laminated by coating and 1
A laminated body is obtained in which the 80 nm primer layer second layer 2 is laminated on the 00 nm primer layer first layer. Further, vacuum evaporation is performed by an electron beam heating method to add 40 to 50 silicon oxide.
The layers were laminated so as to have a thickness of nm to obtain a layered product of the present invention.

Example 4 Primer 1B was applied to one side of a biaxially stretched polyethylene terephthalate film (12 μm).
And primer 2B are sequentially laminated by coating, and 1
A layered product is obtained in which the primer layer second layer 2 of 500 nm is laminated on the primer layer first layer of 00 nm. Further, vacuum evaporation is performed by an electron beam heating method to add 40 to 5 silicon oxide.
The layers were laminated so as to have a thickness of 0 nm to obtain a layered product of the present invention.

Example 5 A primer 1C was formed on one side of a biaxially stretched polyethylene terephthalate film (12 μm).
And primer 2A are sequentially laminated by coating and 1
A laminated body in which a 80 nm-thick primer layer second layer is laminated on a 00-nm primer layer first layer is obtained. Further, vacuum evaporation is performed by an electron beam heating method to add 40 to 50n of silicon oxide.
The laminate of the present invention was obtained by laminating so as to have a thickness of m.

Example 6 Primer 1C was applied to one side of a biaxially stretched polyethylene terephthalate film (12 μm).
And primer 2B are sequentially laminated by coating, and 1
A laminated body in which a 500 nm-thick primer layer second layer is laminated on a 00-nm primer layer first layer is obtained. Further, vacuum evaporation is performed by an electron beam heating method to add 40 to 50 silicon oxide.
The layers were laminated so as to have a thickness of nm to obtain a layered product of the present invention.

<Comparative Example 1> An untreated product of a biaxially stretched polyethylene terephthalate film (12 μm) was vacuum-deposited by an electron beam heating method to deposit silicon oxide at 40 to 50 nm.
To obtain a laminated body.

An unstretched polyethylene film having a thickness of 50 μm was laminated on the laminates of Examples 1 to 6 and Comparative Example 1 through a urethane adhesive layer by a dry lamination method.

<Test 1> The laminate strength of the laminates of Examples 1 to 6 and Comparative Example 1 laminated as described above was measured by Tensilon. The peeled portion is a primer layer and a silicon oxide layer, a silicon oxide layer, or an adhesive layer. 1 sample
A strip type with a width of 5 mm. The measurements were taken at 180 ° peel with the substrate straightened. Measurement conditions are crosshead speed 300m
It was performed at m / min.

<Test 2> The oxygen permeability of the laminates of Examples 1 to 6 and Comparative Example 1 laminated as described above was measured. The measurement is OXTRAN 50/1 made by Modern Control.
The measurement was performed under the conditions of a temperature of 25 ° C. and a relative humidity of 100% using a 0 type oxygen permeability measuring device.

<Test 3> Using the laminates of Examples 1 to 6 and Comparative Example 1 laminated as described above, a pouch with a four-sided seal was prepared, and about 25 g of toothpaste was filled as the content, and 40
It was stored in an atmosphere of ℃ -90% RH for 3 months, and the change in laminate strength was measured over time. The measurement conditions were the same as in Test 1 above.

<Test Results> The test results are summarized in Table 1. The results of Test 1 show that the laminate strength is improved by providing the primer layer. However, if the coating amount of the second layer of the primer layer was too large, then under the drying conditions of this time, curing failure occurred and adhesion could not be obtained. Further, in Test 2, it was found that high barrier properties were obtained by providing the primer layer. In Test 3, in the comparative example, the adhesiveness was deteriorated by filling the content, whereas the film provided with the primer layer of the present invention maintained a high level of adhesiveness, and the content resistance was high. You can see that it is excellent.

[0044]

[Table 1]

[0045]

As described above, according to the present invention, it has a high barrier property and is excellent in adhesiveness when laminating,
In addition, a versatile packaging material having excellent adhesiveness over time when the contents are filled can be obtained. Further, the melamine resin, which is the second layer of the primer layer, is a thermosetting resin, and since a high temperature is applied to cure it, the aging necessary for curing the first layer of the primer layer can be omitted. It also has the effect of imparting the thermal stability of.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a strongly adherent transparent laminate having a gas barrier property of the present invention.

[Explanation of symbols]

 Plastic base material 11 Transparent primer layer 1st layer 12 Transparent primer layer 2nd layer 13 Transparent barrier layer 14

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location // C08L 75/06 C08L 75/06

Claims (2)

[Claims] 1. A structure in which two different transparent primer layers and a barrier thin film layer made of an inorganic compound are sequentially laminated on a base material made of a transparent plastic material, and the first layer of the transparent primer layer is a polyester resin. A strong adhesion transparent laminate having gas barrier properties, wherein the second layer is a layer made of a mixture of isocyanate resins and the second layer is a layer made of a melamine resin. 2. A strong adhesion transparent film having gas barrier properties according to claim 1, wherein the barrier thin film layer made of the inorganic compound is aluminum oxide, magnesium oxide, tin oxide, silicon oxide, or a mixture thereof. Laminate.