JPH0360772A - Laminated sheet having film for sealant and its production - Google Patents

Abstract

PURPOSE:To shorten the time for producing the laminated sheet by applying the solvent soln. of an electron curing type resin on a base material film and drying the solvent, then bringing a film for sealant into tight contact with the above-mentioned resin and irradiating the film with electron beams. CONSTITUTION:The solvent soln. dissolved with the electron curing type resin is applied on the base material film 11 and after the solvent is dried, the film 13 for sealant is brought into tight contact with the electron curing type resin 12. The electron curing type resin is irradiated with the electron beams to cure and to form the laminated sheet 10 having the film for sealant. A polyether-based polyurethane resin and polyester-based polyurethane resin having an acryloyl group or methacryloyl group are adequate as the above-mentioned electron curing type resin. An alcohol solvent and a solvent mixture composed of the alcohol solvent and water are adequate as the above-mentioned solvent.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention relates to a laminated sheet for forming a sealant film and a method for producing the same, and particularly relates to a sealant film that can be produced in a short time. The present invention relates to a laminated sheet and a method for manufacturing the same.

(Prior Art) Conventionally, as a laminated sheet having a sealant film, one in which a base film, a sealant, and a sealant film are sequentially laminated is known. Among these adhesives, for example, a polyester polyurethane resin or the like is crosslinked and cured with an isocyanate-based curing agent.

A laminated sheet containing such a sealant film is produced as follows.

That is, first, the adhesive is dissolved using a solvent such as ethyl acetate, and this is applied to the base film. Next, the solvent in the applied adhesive is dried, and then the sealant film is brought into close contact with the adhesive. Next, it is left to stand in an atmosphere of about 40° C. for about 7 days (aging step) to create a laminated sheet having a sealant film.

(Problems to be Solved by the Invention) As described above, since conventional laminated sheets undergo an aging process, there is a problem in that the manufacturing time is long. For this reason, it takes a long time to determine whether or not the adhesion state is good, which poses a problem in that production control becomes difficult. Furthermore, if ethyl acetate used as a solvent remains, a problem arises in that it emits an odor.

The present invention has been made in consideration of these points,
It is an object of the present invention to provide a laminated sheet having a sealant film that can be manufactured in a short time and with relatively low odor, and a method for manufacturing the same.

[Structure of the invention]

(Means for Solving the Problems) The present invention applies an electron beam curable resin dissolved in a solvent to a base film, and then, after drying the solvent,
A method for producing a laminated sheet having a sealant film, the method comprising bringing a sealant film into close contact with the electron beam curable resin, and further irradiating the electron beam curable resin with an electron beam, and a base film. , a laminated sheet comprising an electron beam curable resin and a sealant film produced by the above manufacturing method, wherein the electron beam curable resin is cured by electron beam irradiation. be.

(Function) According to the present invention, there is no need to provide aging step 11 during the manufacturing process, and the IV! The laminated sheet can be obtained immediately by the 1 qt process).

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of the present invention. In FIG. 1, a laminated sheet 10 having a sealant film is constructed by sequentially laminating a base film 11, an electron beam curable resin 12, and a sealant film 13.

Next, a method for manufacturing a laminated sheet having such a structure will be described.

First, the electron beam curable resin 12 dissolved in a solvent is applied to the base film 11 . After that, after drying the solvent, the sealant film 13 is applied to the electron beam curable resin 12.
bring them into close contact. Subsequently, the electron beam curable resin 12 is irradiated with an electron beam from the base film 11 side to cure the electron beam curable resin 12. In this way, a laminated sheet 10 in which the base film 11 and the sealant film 13 are closely adhered to each other by the electron beam curable resin 12 is obtained.

Next, the materials of each member will be explained in detail.

Base film The base film includes, for example, a biaxially oriented polypropylene film, a biaxially oriented polyester film, a biaxially oriented polyamide film 1', a single layer film or a laminated film, or a laminate of the above film and metal foil or paper. Film etc. can be used.

Note that the base film may be printed in advance.

Sealant films laminated to the base film include, for example, low density polyethylene film, medium density polyethylene film, high density polyethylene film, ethylene-vinyl acetate copolymer film, ethylene-vinyl acetate copolymer film, etc.
α-olefin” (polyolefin resin films such as polymer films and unstretched polypropylene films can be used.

Electron beam curable resin As the electron beam curable resin, oligomers having a molecular weight of 300 to 6,000, preferably 1,000 to 3,000 are made of epoxy (meth)acrylate, polyurethane (meth)acrylate, polyolefin glycol (meth)acrylate, polyester (meth)acrylate, etc. An oligomer having two or more polymerizable functional groups, that is, an oligomer having a polymerizable double bond, and an acrylic or methacrylic double bond can be used. Among such electron beam curable resins, epoxy (meth)acrylates include those obtained by reacting an epoxy resin having a glycidyl group at the end with acrylic acid, methacrylic acid, etc., such as bisphenol A type epoxy (meth)acrylates. Epoxy acrylate is used. Furthermore, as the polyurethane (meth)acrylate, a product obtained by reacting a polyurethane resin having an isocyanate group at the end with a compound having a vinyl group and a hydroxyl group in the molecule, such as 2-hydroxyethyl acrylate or methacrylate, is used. . Further, as the polyolefin glycol (meth)acrylate, for example, diacrylic ester or dimethacrylic ester of polyethylene glycol is used. Further, as the polyester (meth)acrylate, a polyester made of phthalic anhydride and diethylene glycol treated with acrylic acid or methacrylic acid is used.

Note that the above-mentioned (meth)acrylic-modified oligomers can also be used as a mixture thereof.

Solvent As a solvent for dissolving the electron beam curable resin, a single solvent such as isopropyl alcohol, ethyl alcohol, methyl alcohol, butyl alcohol, or a mixed solvent thereof is used, and in some cases, water may be used in combination.

Next, the method of applying the electron beam curable resin to the base film and the method of irradiating the electron beam will be described in detail.

The electron beam curable resin 12 has a solid content of 10 to 6096 in the solvent,
The base film 1 is dissolved in a solvent of about 40 to 90% by weight.
1.

In addition, when applying the electron beam curable resin 12 dissolved in a solvent to the surface of the base film 11, coating methods such as gravure coating, direct coating, reverse roll coating, etc. are suitable, for example.

The coating amount of the electron beam curable resin 12 is usually 0.5
It is generally about 10 g (solid content)/e.

In addition, the electron beam curable resin 12 is coated with a rolling film 1.
Electron beam irradiation is performed from the first side, but this electron beam irradiation is
This is carried out using commonly used electron beam irradiation equipment. The most preferable electron beam irradiator is a curtain-type accelerator using a filament method. This filament-type curtain accelerator is shielded with a lead lining to prevent the electron beam from leaking outside, and the attached equipment for handling the irradiated object is also self-shielding, making it highly safe. be. Furthermore, this filament type curtain accelerator irradiates a uniform electron beam from a linear filament in a curtain shape, making it easy to control the amount of electron beam irradiation.

In addition, in the electron beam irradiation process, if the line speed of the irradiation amount is too fast, the irradiation will be insufficient and the curing of the electron beam curable resin 12 will be poor. This causes deterioration of the physical properties of the sealant film 13 due to this, resulting in adverse effects such as a decrease in heat sealing performance.

Therefore, it is necessary to set appropriate conditions depending on the situation, such as the dose during irradiation and the line speed during irradiation.

Note that the electron beam irradiation may be performed from the base film 11 side as described above, or from the sealant film 13 side;
It is preferable to do it from the side.

(Specific example 1) The present invention will be explained in detail below.

The back surface of the base film 11 made of a biaxially stretched polyester film with a thickness of 12 μm was printed using a one-component general-purpose type back printing ink “RAMIC F: Large [J Area Ratio” manufactured by Nigyo ■], and further, the above-mentioned An electron beam curable resin 12 having the following composition dissolved in a solvent was applied to the printed surface by gravure roll coating at a ratio of 3 g (solid content)/rd. Furthermore, hot air at 80° C. was blown for 0.2 seconds onto the surface coated with the electron beam curable resin 12 to evaporate the solvent and dry it.

Composition Electron beam curable resin "Polyether-based polyurethane diacrylate prepared by treating the reaction product of polyethylene glycol and tolylene diisocyanate with hydroxyethyl acrylate: average molecular weight Hk3000J...
・30 parts solvent "isopropyl alcohol"...70% by weight, then,
A sealant film 13 made of a low-density polyethylene film having a thickness of 60 μm was brought into close contact with the electron beam curable resin 12, and further pressure-bonded with nip rolls. Next, we installed a filament-type curtain accelerator electron beam irradiation device (U.S. E,
(manufactured by S, I, Inc.), dose: 2 Mrad,
Electron beam irradiation was performed from the sealant film 13 side at a line speed of 1,00 m/min to obtain a laminate sheet 10 having the sealant film of the present invention immediately after the heat irradiation process.

(Specific Example 2) The base film 11, sealant film 13, electron beam curable resin 12, and solvent used in Specific Example 1 were used. Then, the laminated sheet 1 was prepared in the same manner as in Example 1 except that electron beam irradiation was performed from the base film 11 side.
I got 0.

(Comparative Example) Next, a laminated sheet using an isocyanate-curable polyether polyurethane resin instead of an electron beam-curable resin was manufactured as a comparative example, and this comparative example was compared with the above specific examples 1 and 2. .

That is, on the printed surface of the base film 11 used in Example 1, an isocyanate-curable polyether polyurethane resin "Takelac A-" using ethyl acetate as a solvent was applied.
969, Takenate A-5: Manufactured by Takeda Pharmaceutical Company Ltd.'' was applied at a ratio of 3 g (solid content)/e, and the same adhesive as used in Example 1 was applied to the coated surface. The density polyethylene film (sealant film 13) was tightly bonded and crimped with a nip roll, and then
A laminated sheet of a comparative example was obtained by aging at 7 days.

Comparative Experiment 1 The lamination strength of each laminated sheet obtained in Specific Examples 1 and 2 and Comparative Example was measured.

Comparative experiment method: Each laminated sheet was cut into a narrow tape shape with a width of 15 mm, and the base film 11 and the sealant film 13 were peeled at a peeling angle of 90 degrees and a speed of 300 m+m/mln.

The results are shown in the table below.

Comparative Experiment 2 Comparative Experiment Method: Each laminated sheet obtained in Specific Examples 1 and 2 and Comparative Example was cut into 10100 x 100 pieces, and 5 sheets each were cut into 200 m pieces.
The mixture was sealed in a 1-volume Erlenmeyer flask with a stopper and left in an oven at 40°C for 1 hour, after which the odor was evaluated. As a result, the laminated sheets obtained in Specific Examples 1 and 2 were odorless, but the laminated sheets obtained in Comparative Example had a residual odor due to ethyl acetate.

As explained above, according to the present invention, the laminated sheet 10
There is no change in the aging process during the process of obtaining the laminate sheet, and the laminated sheet can be obtained immediately upon completion of the electron beam irradiation process, so the manufacturing process is extremely shortened. Therefore, it is possible to determine whether or not the adhesive state between the base film 11 and the sealant film 13 is good immediately after the electron beam irradiation treatment, which facilitates production management.

Further, in the present invention, since an alcohol-based solvent is used to dissolve the electron beam curable resin 12, the problem of odor caused by residual solvent can be solved. Therefore, it is particularly convenient for obtaining laminated sheets used as food packaging materials. Furthermore, since the electron beam curable resin 12 is dissolved by the solvent solution, the viscosity of the electron beam curable resin 12 can be easily adjusted. Further, according to this example, high lamination strength can be obtained as in the comparative example.

〔Effect of the invention〕

As explained above, according to the present invention, a laminated sheet can be obtained immediately upon completion of the electron beam irradiation treatment. In addition, since it is possible to shorten the time of the manufacturing process,
It is possible to determine in a short time whether the adhesion state of the laminated sheet is good or bad, thereby making it possible to improve the efficiency of production management.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing an example of a laminated sheet having a sealant film according to the present invention. DESCRIPTION OF SYMBOLS 10... Laminated sheet, 11... Base material, 12... Electron beam curable resin, 13... Film for sealant.

Claims (1)

[Claims] 1. Applying an electron beam curable resin dissolved in a solvent to a base film, then drying the solvent, and then bringing a sealant film into close contact with the electron beam curable resin; A method for manufacturing a laminated sheet having a sealant film, further comprising irradiating the electron beam curable resin with an electron beam. 2. The method for producing a laminated sheet having a sealant film according to claim 1, wherein the electron beam curable resin is a polyether polyurethane resin or a polyester polyurethane resin having an acroyl group or a metaacroyl group. 3. The method for producing a laminated sheet having a sealant film according to claim 1 or 2, wherein the solvent is an alcoholic solvent or a mixed solvent of an alcoholic solvent and water. 4. The method for producing a laminated sheet having a sealant film according to any one of claims 1 to 3, wherein the base film is printed. 5. Produced by the method according to claim 1, comprising a base film, an electron beam curable resin, and a sealant film, and wherein the electron beam curable resin is cured by electron beam irradiation. Laminated sheet with sealant film.