METHOD FOR MANUFACTURING FLEXIBLE PACKAGING FILM

Abstract

A method for producing a flexible packaging film including a substrate and a polyurethane adhesive that is applied to the substrate and is a mixture of an A agent and a B agent includes a two-part separate application step that includes bringing a mixture of the A agent and B agent applied to one substrate into contact with a catalyst applied to another substrate and pressing the substrates, wherein the A agent is a polyisocyanate compound, and the B agent is a polyol compound. The polyol compound is preferably a polymer polyol comprising a polyether polyol or a polyester polyol as an essential component.

Claims

1. A method for producing a flexible packaging film comprising a substrate and a polyurethane adhesive that is applied to the substrate and is a mixture of an A agent and a B agent, the method comprising: a two-part separate application step that comprises bringing a mixture of the A agent and the B agent applied to one substrate into contact with a catalyst applied to another substrate and pressing the substrates, wherein the A agent is a polyisocyanate compound, and the B agent is a polyol compound.

2. The method for producing a flexible packaging film according to claim 1, wherein the polyol compound is a polymer polyol comprising a polyether polyol or a polyester polyol as an essential component.

3. The method for producing a flexible packaging film according to claim 1, wherein the polyisocyanate compound is an isocyanate compound having at least two isocyanate groups in the molecule thereof.

4. The method for producing a flexible packaging film according to claim 1, wherein the catalyst comprises at least one catalyst selected from a metal catalyst, an amine catalyst, a diazabicycloundecene catalyst, an aliphatic cyclic amide compound, and a titanium chelate complex.

5. The method for producing a flexible packaging film according claim 1, wherein the substrate is a plastic film, a deposited metal film, or a metal foil.

6. The method for producing a flexible packaging film according to claim 2, wherein the polyisocyanate compound is an isocyanate compound having at least two isocyanate groups in the molecule thereof.

7. The method for producing a flexible packaging film according to claim 2, wherein the catalyst comprises at least one catalyst selected from a metal catalyst, an amine catalyst, a diazabicycloundecene catalyst, an aliphatic cyclic amide compound, and a titanium chelate complex.

8. The method for producing a flexible packaging film according to claim 3, wherein the catalyst comprises at least one catalyst selected from a metal catalyst, an amine catalyst, a diazabicycloundecene catalyst, an aliphatic cyclic amide compound, and a titanium chelate complex.

9. The method for producing a flexible packaging film according to claim 6, wherein the catalyst comprises at least one catalyst selected from a metal catalyst, an amine catalyst, a diazabicycloundecene catalyst, an aliphatic cyclic amide compound, and a titanium chelate complex.

10. The method for producing a flexible packaging film according to claim 2, wherein the substrate is a plastic film, a deposited metal film, or a metal foil.

11. The method for producing a flexible packaging film according to claim 3, wherein the substrate is a plastic film, a deposited metal film, or a metal foil.

12. The method for producing a flexible packaging film according to claim 4, wherein the substrate is a plastic film, a deposited metal film, or a metal foil.

13. The method for producing a flexible packaging film according to claim 6, wherein the substrate is a plastic film, a deposited metal film, or a metal foil.

14. The method for producing a flexible packaging film according to claim 7, wherein the substrate is a plastic film, a deposited metal film, or a metal foil.

15. The method for producing a flexible packaging film according to claim 8, wherein the substrate is a plastic film, a deposited metal film, or a metal foil.

16. The method for producing a flexible packaging film according to claim 9, wherein the substrate is a plastic film, a deposited metal film, or a metal foil.

Description

EXAMPLES

[0057] Hereinbelow, the present invention will be described in detail with reference to the following Examples.

Example 1

[0058] A mixture (hereinafter, referred to as “adhesive mixture (1)”) of aromatic polyether isocyanate 2K-SF-220A (A agent) and polyether polyol HA-220B (B agent), each of which is manufactured by DIC Corporation, was applied as an adhesive at 1.5 g/m.sup.2 onto a 20 μm OPP (biaxially oriented polypropylene) film which had been printed. On the other hand, a mixture of 6 parts of ε-caprolactam and 94 parts of HA-220B was applied as a catalyst liquid at 0.2 g/m.sup.2 onto 30 μm CPP (cast polypropylene), and the applied surfaces of the respective films were put together and pressed using nip rolls (nip rolls temperature: 50° C.) to produce a plastic film laminate. The pressing speed was 200 m/min, and the adhesive coating weight was 1.7 g/m.sup.2.

[0059] The amounts of the agents were controlled so that the ratio of 2K-SF-220A and HA-220B incorporated became 10/7.

Example 2

[0060] A plastic film laminate was produced in substantially the same manner as in Example 1 except that, as a catalyst liquid applied to the 30 μm CPP (cast polypropylene), a mixture of 1 part of a photo-latent titanium catalyst, 5 parts of ε-caprolactam, and 94 parts of HA-220B was applied at 0.2 g/m.sup.2.

Example 3

[0061] A plastic film laminate was produced in substantially the same manner as in Example 1 except that, as a catalyst liquid applied to the 30 μm CPP (cast polypropylene), a mixture of 0.4 part of dibutyltin dilaurate and 99.6 parts of HA-220B was applied at 0.2 g/m.sup.2.

Example 4

[0062] A plastic film laminate was produced in substantially the same manner as in Example 1 except that, as a catalyst liquid applied to the 30 μm CPP (cast polypropylene), a mixture of 1 part of a photo-latent titanium catalyst, 5 parts of ε-caprolactam, and 94 parts of HA-220B was applied at 0.4 g/m.sup.2, and that the pressing speed was 200 m/min and the adhesive coating weight was 1.9 g/m.sup.2.

Example 5

[0063] A plastic film laminate was produced in substantially the same manner as in Example 1 except that, as a catalyst liquid applied to the 30 μm CPP (cast polypropylene), a mixture of 1 part of a photo-latent titanium catalyst, 5 parts of ε-caprolactam, and 94 parts of HA-220B was applied at 0.1 g/m.sup.2, and that the pressing speed was 200 m/min and the adhesive coating weight was 1.5 g/m.sup.2.

Comparative Example 1

[0064] The adhesive mixture (1), which is a mixture of 2K-SF-220A (A agent) and polyether polyol HA-220B (B agent), was applied to the ink surface of a 20 μm OPP (biaxially oriented polypropylene) film which had been printed, and the applied surface and the corona treated surface of 30 μm CPP (cast polypropylene) were put together and pressed using nip rolls (nip rolls temperature: 50° C.) to produce a plastic film laminate. The pressing speed was 200 m/min, and the adhesive coating weight was 1.5 g/m.sup.2. The amounts of the agents were controlled so that the ratio of 2K-SF-220 and HA-220B incorporated became 10/7.

Comparative Example 2

[0065] 2K-SF-220A (A agent) was applied at 1.0 g/m.sup.2 onto a 20 μm OPP (biaxially oriented polypropylene) film which had been printed. On the other hand, polyether polyol HA-220B (B agent) was applied at 0.7 g/m.sup.2 onto 30 μm CPP (cast polypropylene), and the applied surfaces of the respective films were put together and pressed using nip rolls (nip rolls temperature: 50° C.) to produce a plastic film laminate. The pressing speed was 200 m/min, and the adhesive coating weight was 1.7 g/m.sup.2.

Comparative Example 3

[0066] A mixture of 2K-SF220A (A agent) at 1.0 g/m.sup.2 and ε-caprolactam at 0.012 g/m.sup.2 was applied onto a 20 μm OPP (biaxially oriented polypropylene) film which had been printed. On the other hand, polyether polyol HA-220B (B agent) was applied at 0.7 g/m.sup.2 onto 30 μm CPP (cast polypropylene), and the applied surfaces of the respective films were put together and pressed using nip rolls (nip rolls temperature: 50° C.) to produce a plastic film laminate. The pressing speed was 200 m/min, and the adhesive coating weight was 1.7 g/m.sup.2.

Comparative Example 4

[0067] 2K-SF220A (A agent) was applied at 1.0 g/m.sup.2 onto a 20 μm OPP (biaxially oriented polypropylene) film which had been printed. On the other hand, a mixture of HA-220B (B agent) at 0.7 g/m.sup.2 and c-caprolactam at 0.012 g/m.sup.2 was applied onto 30 μm CPP (cast polypropylene), and the applied surfaces of the respective films were put together and pressed using nip rolls (nip rolls temperature: 50° C.) to produce a plastic film laminate. The pressing speed was 200 m/min, and the adhesive coating weight was 1.7 g/m.sup.2.

[0068] The results of the evaluation of the pot life and curing rate during the production of the laminate are shown in Table 1.

(Method for Judgment)

(Formulation Control)

[0069] The criteria for judgment are as follows.

[0070] ◯: Formulation control is possible in advance in terms of a weight.

[0071] Δ: Formulation control is impossible unless a coating weight meter is used.

[0072] X: Formulation control is impossible.

(Pot Life)

[0073] According to the formulation of a coating method shown in Table 1 below, an adhesive was blended and, immediately after being blended, about 0.8 g of the adhesive was placed on the measuring site of a rheometer, and a viscosity was measured for 30 minutes at a temperature such that the viscosity of the adhesive immediately after being blended became about 1,000 mPa.Math.s. From the viscosity value measured at the time of the start of the measurement and the viscosity value measured 30 minutes after the start, evaluation was made as follows.

[0074] Evaluation ⊙: The viscosity measured 30 minutes after the start is 1 to less than 2 times the viscosity of the blend at the time of the start.

[0075] Evaluation ◯: The viscosity measured 30 minutes after the start is 2 to less than 3 times the viscosity of the blend at the time of the start.

[0076] Evaluation Δ: The viscosity measured 30 minutes after the start is 3 to less than 4 times the viscosity of the blend at the time of the start.

[0077] Evaluation X: The viscosity measured 30 minutes after the start is 4 or more times the viscosity of the blend at the time of the start.

[0078] Acceptance limit: ◯ Or more excellent [0057]

(Curing Rate)

[0079] The plastic film laminate obtained after pressed was matured in an atmosphere at 40° C. for 24 hours, and then subjected to infrared absorption spectrum measurement in a transmission mode to measure an absorption spectrum ascribed to an isocyanate (around 2,270 cm.sup.−1).

[0080] ⊙: The isocyanate reaction ratio is 90% or more.

[0081] ◯: The isocyanate reaction ratio is 80% or more.

[0082] Δ: The isocyanate reaction ratio is 70% or more.

[0083] X: The isocyanate reaction ratio is 50% or more.

[0084] Acceptance limit: ◯ Or more excellent

TABLE-US-00001 TABLE 1 Coating liquid applied Coating liquid applied to to OPP film and CPP film and coating Formulation coating weight weight control Pot life Curing rate Example 1 Adhesive mixture (1)* Mixture of 6 parts of ◯ ⊙ ⊙ 1.5 g/m.sup.2 ε-caprolactam and 94 parts of HA-220B 0.2 g/m.sup.2 Example 2 Adhesive mixture (1) Mixture of 1 part of ◯ ⊙ ⊙ 1.5 g/m.sup.2 photo-latent titanium catalyst, 5 parts of ε-caprolactam, and 94 parts of HA-220B 0.2 g/m.sup.2 Example 3 Adhesive mixture (1) Mixture of 0.4 part of ◯ ⊙ ⊙ 1.5 g/m.sup.2 dibutyltin dilaurate and 99.6 parts of HA-220B 0.2 g/m.sup.2 Example 4 Adhesive mixture (1) Mixture of 6 parts of ◯ ⊙ ⊙ 1.5 g/m.sup.2 ε-caprolactam and 94 parts of HA-220B 0.4 g/m.sup.2 Example 5 Adhesive mixture (1) Mixture of 6 parts of ◯ ⊙ ◯ 1.5 g/m.sup.2 ε-caprolactam and 94 parts of HA-220B 0.1 g/m.sup.2 Comparative Adhesive mixture (1) None ◯ ◯ Δ Example 1 1.5 g/m.sup.2 Comparative 2K-SF220A HA-220B Δ ⊙ Δ Example 2 1.0 g/m.sup.2 0.7 g/m.sup.2 Comparative Mixture of 2K-SF220A HA-220B Δ ⊙ ◯ Example 3 1.0 g/m.sup.2 and 0.7 g/m.sup.2 ε-caprolactam 0.012 g/m.sup.2 Comparative 2K-SF220A Mixture of HA-220B 0.7 Δ ⊙ ◯ Example 4 1.0 g/m.sup.2 g/m.sup.2 and ε-caprolactam 0.012 g/m.sup.2

[0085] The abbreviations and *1 shown in Table 1 indicate the followings. [0086] OPP: Biaxially oriented polypropylene [0087] CPP: Cast polypropylene [0088] *1: Adhesive mixture (1) means a mixture of aromatic polyether isocyanate 2K-SF-220A (A agent) and polyether polyol HA-220B (B agent), each of which is manufactured by DIC Corporation. 2K-SF220A: Aromatic polyether isocyanate, manufactured by DIC Corporation [0089] HA-220B: Polyether polyol, manufactured by DIC Corporation

[0090] With respect to the flexible packaging film obtained by the method for producing a flexible packaging film of the invention having the separate application step, the pot life of the adhesive during the production of the film is extended and the curing rate is high, and a method for producing such a flexible packaging film can be provided.