JP2003236939A - Apparatus for laminating film and method for manufacturing laminated film using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To introduce truly suitable laminating conditions without bringing about an appearance fault in a solventless type laminated film and to further allow a PET film and a VMCPP film particularly desired to be improved in an appearance to be laminated. <P>SOLUTION: The apparatus for laminating the film comprises a first laminating unit for impressing the base film to a laminating film after the base film is covered with the adhesive in the manufacture of the laminated film to be worked by the solventless type adhesive, and a second laminating unit for impressing again the laminated film immediately thereafter. In this apparatus, a tension between the first laminating unit and the second laminating unit of the apparatus can be freely controlled. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film laminating apparatus in which two films are laminated with a solventless adhesive and a method for producing a laminated film using the film laminating apparatus. The present invention relates to a laminated film manufacturing apparatus and manufacturing method that suppress satin finish and have a good appearance. In particular, the present invention relates to an apparatus and method for producing a laminated film capable of improving the appearance of a polyester film / adhesive / aluminum vapor-deposited polypropylene film (unstretched and stretched), which has been said to cause defective appearance.

[0002]

2. Description of the Related Art Conventionally, as a laminating method for obtaining a flexible composite packaging material, an adhesive agent dissolved in an organic solvent is applied to the surface of a plastic film, and the solvent is evaporated by hot air or heating to dry it, and then laminated. There is known a solvent-type dry lamination method in which films to be stacked are superposed and heated and pressed. This method is more costly than the wet lamination method in which bonding is performed while the adhesive is in a wet state, but the bonding process can be performed efficiently at high speed, and the type of adhesive and its coating amount can be adjusted. Since it can be applied to almost all films by selection, various laminated films having various properties required for packaging materials can be manufactured. FIG. 4 shows a schematic configuration of a solvent type laminator 20 that performs this dry lamination method. An outline of the solvent-type dry lamination process will be described with reference to FIG. 4. An adhesive 24 is applied to the first base material 21 through a coating part 25 (generally a gravure coating method is used). After that, the adhesive 24 is dried by passing through the drying zone 26 (generally, a hot air blowing method of 80 to 120 ° C. is adopted), and then the first base material 21 that has become an adhesive state through a drying step. The adhesive roll and the second base material 22 are attached to the rubber roll 27a.
Then, the dry laminating section DL consisting of the heating metal roll 27b is nipped and thermocompression bonded. At this time, the heating metal roll 27b is heated to 60 to 80 ° C. After that, it is cooled by the cooling roll 28 and wound up. In addition, the laminated film 23 that has been wound up is used to accelerate the curing of the adhesive 24.
Aging treatment is performed at 5 to 45 ° C.

Among the laminated films produced through such steps, those used as packaging materials for foods employ a film having a high elastic modulus, heat resistance and dimensional stability as the outer film, and As the film on the content side, an aluminum vapor-deposited film having a heat-sealing property that softens at a relatively low temperature and a gas barrier property to prevent the solvent from leaking to the content side is adopted. Laminate films, which are the mainstream as packaging materials for such food products, are shown in FIGS. 6 (a) and 6 (b). Both of the base films 2e and 2op are bonded to each other with the inner film 3 and the adhesive layer 4 interposed therebetween.
Is an aluminum vapor deposited polypropylene (VMCPP) film. The films 2e and 2op are respectively a polyester (PET) film and a biaxially oriented polypropylene (O) film.
PP) film. Here, the PET film in the laminated film 1'of FIG. 6 (a) has properties such as excellent heat resistance and dimensional stability, high rigidity and high strength. Compared to the PET film with respect to such properties, the OPP film is inferior, but has advantages such as excellent moisture resistance and low price. Therefore, the laminated film 1 ″ of FIG. It is widely used in packaging for snacks, etc. On the other hand, the dry lamination method using an adhesive containing an organic solvent such as the one described above is not suitable for environmental pollution caused by organic solvents, problems in the Fire Defense Law, and solvent costs. Currently, there are various problems such as problems (including equipment costs for solvents), etc. In the field of food packaging, laminated films using solvent-type adhesives have residual solvent odor. Therefore, in recent years, manufacturers have provided adhesives that do not contain organic solvents, so-called solventless adhesives. There are some food packaging materials on the market with laminated films laminated together.This type of laminated film has various advantages such as energy saving, resource saving, environmental problems and no residual solvent. Therefore, it is considered that the number of laminated films using a solventless adhesive will increase in the future while coexisting with the laminated films using a solvent type adhesive.

[0004]

By the way, as shown in FIG. 5, a laminate film produced by a solventless laminator and produced by a laminating method using a solventless adhesive containing no organic solvent (hereinafter referred to as solventless Type laminate film) has a problem that its finished appearance is not good as compared with the solvent type laminate film. That is, immediately after lamination, there are minute spot-like defects (foaming) both on the ground and on the printed surface.
The appearance of small irregularities (matte finish) is often experienced, and this poor appearance disappears mostly after aging treatment, but depending on the type of film, foaming or satin finish remains and the packaging material may show poor appearance. is there. Various improvements have been made on the operation side at the laminating site in order to suppress the occurrence of such a defective appearance, but it has not been completely solved. As a typical laminated film that combines specific films that are particularly noticeable with poor appearance,
Laminated films 1 ', 1 "that combine the biaxially stretched polyester film 2e and the vapor-deposited polypropylene film 3 shown in FIG. 6 (a) or the biaxially stretched polypropylene film 2op and the vapor-deposited polypropylene film 3 shown in FIG. 6 (b) can be given. In this type of film, since minute spot-like defects and small irregularities do not disappear in a visually observable state, as a result, they have a poor appearance and cannot be used as a packaging material. The purpose of is to derive a truly suitable laminating condition in which a defective appearance does not occur in a solvent-free type laminated film, and further improvement of the appearance is particularly desired.
It is possible to laminate ET film with VMCPP film and VMOPP.

[0005]

The above-mentioned problems can be solved by the present invention described below. That is, in the invention described in claim 1, in the production of a laminated film processed with a solventless adhesive, the adhesive is applied to a base film, and then the base film and the laminating film are pressure-bonded. 1
The film laminating apparatus is characterized in that a laminating section and a second laminating section for immediately pressing the laminating film again are provided immediately after the laminating section. The invention described in claim 2 is characterized in that the tension between the first laminate portion and the second laminate portion according to claim 1 can be freely controlled. The invention described in claim 3 uses the laminating apparatus according to claim 1 or 2, and the temperature of the roller of the first laminating section is 50 ° C.
The method for producing a laminated film is characterized in that heating is performed at 100 ° C. or higher and the temperature of the roller in the second laminating section is set to 0 ° C. or higher and lower than 50 ° C. The invention described in claim 4 uses the laminating apparatus according to claim 1 or 2, and the tension between the first laminating portion and the second laminating portion is 0 kg.
The manufacturing method is characterized by being adjusted to f / m or more and less than 15 kgf / m. In the invention described in claim 5, the solventless adhesive used in the manufacturing method according to claim 3 or 4 is a two-liquid mixed solventless adhesive whose viscosity is reduced by heating. It is characterized by that.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is an apparatus for laminating a base material film such as a polyester film or a biaxially oriented polypropylene film and a vapor-deposited polypropylene film in a good appearance and processing conditions for processing using the apparatus. Therefore, a detailed description will be given below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a solventless dry laminator used for carrying out the present invention. FIG. 2 is a diagram showing a configuration around a coating portion in the laminator of FIG. FIG. 3 is a configuration diagram of a laminated film manufactured by the method of the present invention.

That is, in the production of a laminated film processed with a solventless adhesive, a laminating section in which the adhesive is applied to a base film, and then the base film and the laminating film are pressure-bonded, and immediately after that, the laminate is laminated again. A film laminating apparatus comprising a laminating section for pressure-bonding a film. Furthermore, the temperature of the roller of the laminating part is heated to 50 ° C. or higher and lower than 100 ° C., and the temperature of the roller of the laminating part is set to 0 ° C. or higher and lower than 50 ° C. Production method. The above tension between the laminating part and the laminating part is 0 kgf / m or more and 15 kgf / m or more.
A method for producing a laminated film, which is adjusted to less than m. The method for producing a laminated film according to claim 1, 2, 3, or 4, wherein the adhesive used is a solventless adhesive of a type whose viscosity is reduced by heating.

As a study for solving the above-mentioned problems, the present inventor adjusted the temperature of the nip roll from 0 ° C. to 90 ° C. in the non-sol laminator shown in FIG. 6, and when the temperature is high, foaming and satin finish are improved. However, there is film damage (barrier deterioration when an inorganic barrier layer such as VMCPP is included) due to film tunneling or tension after heating. At low temperatures, film tunneling and film damage are not observed, but foaming and satin Ascertaining the remarkable occurrence, as shown in FIGS. 1 and 2, the conventional laminating section is used as the first laminating section DL1 and the second laminating section DL2 is newly provided.
By providing the tension control section TC between the first laminating section DL1 and the second laminating section DL2,
They have found that they can solve the problems and have completed the present invention.

The coating portion 15 in the dry laminator using a solventless adhesive is often a 4-roll coating system or a 5-roll coating system. This embodiment has been described by taking an example of a four roll coating method. In the coating part, after the adhesive 14 is applied to the first base material 11, the second adhesive is applied to the adhesive surface of the first base material 11.
The first laminating section DL1 (rubber roll 16a and heating metal roll 16b) is nipped in the first laminating section DL1 (rubber roll 16a and heating metal roll 16b) while passing through the tension control section TC, and then the second laminating section DL2 (rubber roll 17a and heating metal roll 17).
Nip at b). The wound laminated film 13 is subjected to an aging treatment at a temperature of 35 ° C to 45 ° C in order to accelerate the curing of the adhesive.

The coating section 15 is a device for coating the first base material 11 with the adhesive 14 whose viscosity is adjusted to an appropriate value by heating. As shown in FIG. 2, a well-known four roll coating system is adopted. In this configuration, the backup roll 15a (metal), the coating roll 15b (rubber), the metering roll 15c (metal), and the application roll 15d (rubber) are arranged in this order from the top. An adhesive storage portion is provided between the application roll 15d and the metering roll 15c, and the two-liquid mixed solventless adhesive 14 is supplied from the adhesive supply portion 18 to the storage portion. Then, the first base material passes between the backup roll 15a and the coating roll 15b, and the adhesive agent 14 stored in the adhesive agent storing section is fed by the metering roll 15
It is applied to the first base material 11 via c and the coating roll 15b. Here, the backup roll 15a has a heat generating mechanism or the like so that the first base material 11 is sandwiched between the first base material 11 and the backup material.
It is possible to adjust the temperature of the adhesive 14 applied to the opposite side of the. In addition, the coating amount of the adhesive 14 (1 to 2 g / m <2>) by adjusting the interval between the rolls
Can be adjusted.

Since the adhesive supply unit 19 uses the two-liquid type adhesive 14, the system (tank, pump, these pipes) 19a for supplying the main agent 14a of the adhesive 14 is used.
And a system (tank, pump, these pipes) 19b for supplying the auxiliary agent (curing agent) 14b, the main agent 14a and the auxiliary agent 14
It is composed of an application jig 19c which is mixed with b and supplied. Here application jig 19
c is located above the application roll 15d and the metering roll 15c and has a structure capable of scanning in the width direction of both rolls. To supply.

[0013]

EXAMPLE In this example, the temperature of the first laminating section 16 is set to 80 ° C. and the temperature of the second laminating section 37 is set to 20 ° C. by using the non-sol (solventless) laminator shown in FIGS. The tension of the tension control 18 was set to 10 kgf / m. Then, the first layer of the film on which the adhesive 14 is applied, that is, the first base material 11, is PET-coated.
A VMCPP (aluminum vapor-deposited polypropylene) film was used for the (polyester) film and the second layer film to be bonded thereto, that is, the second substrate 12. This combination of films is a combination of films which has hitherto been considered impossible to bond together well. The adhesive is a solventless adhesive (main agent: "A-69" manufactured by Mitsui Takeda Chemical Co., Ltd.
5 ”and an auxiliary agent“ A-95 ”manufactured by Mitsui Takeda Chemical Co., Ltd. were used at a temperature of 70 ° C. (coating viscosity: 660 mmPa · s) for lamination. This adhesive has a compounding viscosity of 60 ° C.
1000 mmPa · s, 80 ° C 430 mmPa · s
When the temperature rises, the viscosity decreases.

[0014]

[Comparative Example 1] A conventional solventless laminator shown in FIG. 5 (tension control, no second laminating section).
The adhesive and the film to be laminated were subjected to the same conditions as in Example. The roll temperature in the laminating unit 36 is set to 8
It was set to 0 ° C.

[Comparative Example 2] The roll temperature in the laminating section 36 is set to 20 ° C.
Lamination was carried out under the same conditions as in Comparative Example 1 except that

[Table 1]

[0015]

As described above, according to the present invention,
When laminating films with a solventless adhesive, foaming and matting are suppressed in the first laminating section, damage to the film is suppressed by the tension control section and the second minating section, and tunneling can be prevented. The above-mentioned foaming as a laminate film for packaging in a film combination that has been considered difficult to commercialize due to the occurrence of poor appearance from the past, a laminate film without the occurrence of matte finish, manufacturing under stable processing conditions without film damage or tunneling. Became possible.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a solventless dry laminator used for carrying out the present invention.

FIG. 2 is a diagram showing a configuration around a coating unit in the laminator of FIG.

FIG. 3 is a constitutional view of a laminated film produced by the method of the present invention.

FIG. 4 is a schematic configuration diagram of a conventional solvent type dry laminator.

FIG. 5 is a schematic configuration diagram of a conventional solventless dry laminator.

FIG. 6 is a configuration diagram of a laminated film manufactured by a conventional dry lamination method.

[Explanation of symbols]

DL laminating section DL1 1st laminating section DL2 Second laminating unit G guide roll TC tension control section SR feed roll unit UW Unwinder RW Rewinder VM evaporation layer 1 Laminated film 2 First base material 2e Polyester film 2op biaxially oriented polypropylene film 3 Second base material 4 adhesive 10 Solventless dry laminating apparatus of the present invention 11 First substrate 12 Second base material 13 Laminated film 14 Adhesive (adhesive storage part) 15 Coating department 15a backup roll 15b coating roll 15c metering roll 15d application role 16a, 17a Pressure rubber roll 16b, 17b Heating metal roll 18 Mixing and supplying section 19 Adhesive supply section 20 Solvent type dry laminating equipment 21 First substrate 22 Second base material 23 Laminated film 24 Solvent type adhesive (adhesive storage part) 25 Coating Department 25a pressure rubber roll 25b heated metal roll 26 Drying zone 27a rubber roll 27b heated metal roll 28 cooling rolls 30 Conventional solventless dry laminating equipment 31 First base material 32 Second base material 33 Laminated film 34 Solventless adhesive (adhesive storage part) 35 Coating Department 35a backup roll 35b coating roll 35c metering roll

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4F211 AA24 AD03 AD08 AM32 AR04                       AR06 TA03 TC02 TC05 TD11                       TH06 TJ30 TN09 TN43 TQ03                       TQ10                 4J040 JA01 JA03 MA02 MA10 MA11                       MB03 NA08 PA30 PA33 PB05                       PB08 PB19

Claims (5)

[Claims] 1. In the production of a laminated film processed with a solventless adhesive, a first laminating section in which the adhesive is applied to a base film and then the base film and the laminating film are pressure-bonded, immediately after that. A film laminating apparatus comprising a second laminating section for pressing the laminating film again. 2. The laminating apparatus according to claim 1, wherein the tension between the first laminating section and the second laminating section can be freely controlled. 3. The laminating apparatus according to claim 1 or 2, wherein the roller of the first laminating unit is heated to a temperature of 50 ° C. or higher and less than 100 ° C., and the roller of the second laminating unit is used. Is set to 0 ° C. or higher and lower than 50 ° C., the method for producing a laminated film. 4. The laminating apparatus according to claim 1 or 2, wherein the tension between the first laminating section and the second laminating section is 0 kgf / m or more and 15 kgf / m or more.
A method for producing a laminated film, which is adjusted to less than m. 5. The laminate film according to claim 3 or 4, wherein the solventless adhesive is a two-liquid mixed solventless adhesive of a type whose viscosity decreases by heating. Production method.