JP4525289B2 - Film for deep drawing packaging, bottom material for deep drawing packaging - Google Patents

Description

  The present invention can be suitably used as a bottom material for deep drawing packaging of foods, etc., and is a single layer or multilayer deep drawing packaging film having a polyamide layer having excellent gas barrier properties, excellent piercing properties, and excellent deep drawability. , And a bottom material for deep-drawing packaging obtained from this film.

Conventionally, as a bottom material for deep drawing packaging of foods, various films excellent in vacuum forming have been used.
Patent Document 1 discloses a multilayer film for packaging composed of at least two layers, the wetting tension of the surface of the first layer serving as the outermost layer (A) is 36 dyn / cm or more, and is on the surface opposite to the first layer. The second layer located is a seal layer (D), the first layer and the second layer are laminated by a coextrusion method, the total thickness is 60 to 200 μm, and deep drawing by vacuum forming or pressure forming A packaging multilayer film is disclosed that is capable of being molded.

  Further, as the terpolymer polyamide, (A) ε-caprolactam and / or ε-aminocaproic acid component, (B) 12-aminododecanoic acid and / or ω-laurolactam component, (C) hexamethylenediamine and Polyamide films obtained by copolymerization with an equimolar salt of adipic acid are disclosed in Patent Document 2 and Patent Document 3.

JP 2004-050517 A Japanese Patent Laid-Open No. 03-106646 Japanese Patent Laid-Open No. 11-071455

Food such as ham is housed in a deep-drawn packaging bottom material and packaged using a lid. With the increase in the volume of food used for packaging, there is a demand for a packaging bottom material having a deep drawing depth that can accommodate and package the food.
The object of the present invention is a film for deep-drawing packaging using polyamide which is excellent in oxygen gas barrier properties, excellent in piercing properties, excellent in deep-drawing formability, and in particular, deep-drawing forming depth as a packaging material for foods and the like. Is to provide.

The present invention is a monolayer or multilayer polyamide film having at least one polyamide layer,
The polyamide layer comprises 50 to 90% by weight of a component selected from (A) ε-caprolactam and ε-aminocaproic acid, (B) a component selected from 12-aminododecanoic acid and ω-laurolactam, and (C) hexamethylene. Copolymerized total amount of diamine and equimolar salt of adipic acid (total amount of B component and C component) 10 to 50% by weight (including 3 components of A component, B component and C component) A film for deep-drawing packaging, characterized in that it is made of polyamide obtained by the following method.

Preferably, the present invention is a multilayer polyamide film of two or more layers having at least one polyamide layer and a thermoplastic resin layer having heat-fusibility in the innermost layer,
The polyamide layer comprises 50 to 90% by weight of a component selected from (A) ε-caprolactam and ε-aminocaproic acid, (B) a component selected from 12-aminododecanoic acid and ω-laurolactam, and (C) hexamethylene. Copolymerized total amount of diamine and equimolar salt of adipic acid (total amount of B component and C component) 10 to 50% by weight (including 3 components of A component, B component and C component) A film for deep-drawing packaging, characterized in that it is made of polyamide obtained by the following method.

The preferable aspect of the film for deep drawing packaging of this invention is shown below. In the present invention, these embodiments can be combined.
(1) The component selected from (A) ε-caprolactam and ε-aminocaproic acid in the polyamide layer is 76 to 84% by weight.
(2) The component selected from (B) 12-aminododecanoic acid and ω-laurolactam in the polyamide layer is 6 to 14% by weight.

  The present invention is a bottom material for deep drawing packaging obtained by deep drawing the film for deep drawing packaging of the present invention.

The deep drawing packaging film of the present invention is excellent in oxygen gas barrier properties as a packaging material for foods, etc., excellent in piercing properties, excellent in deep drawing formability, and can be particularly deeply drawn in deep drawing.
The deep-drawing packaging film of the present invention is excellent in transparency and gloss.
The deep-drawing packaging film of the present invention can provide a deep-drawn bottom material that is excellent in oxygen gas barrier properties, excellent in piercing properties, deep in deep-drawing depth, excellent in transparency and gloss as a packaging material for foods and the like. .

The deep drawing packaging film of the present invention is
A single-layer or multi-layer polyamide film having at least one polyamide layer;
The polyamide layer comprises 50 to 90% by weight of a component selected from (A) ε-caprolactam and ε-aminocaproic acid, (B) a component selected from 12-aminododecanoic acid and ω-laurolactam, and (C) hexamethylene. Copolymerized total amount of diamine and equimolar salt of adipic acid (total amount of B component and C component) 10 to 50% by weight (including 3 components of A component, B component and C component) A film for deep-drawing packaging, characterized in that it is made of polyamide obtained by the following method.
The deep drawing packaging film of the present invention is an unstretched film.

The polyamide layer
50 to 90% by weight of (A) a component selected from ε-caprolactam and ε-aminocaproic acid (component A), and (B) a component selected from 12-aminododecanoic acid and ω-laurolactam (component B) and ( C) The total amount of hexamethylenediamine and the equimolar salt of adipic acid (C component) (the total amount of B component and C component) is 10 to 50% by weight, and the components including A component, B component and C component are combined. This is a layer made of polyamide obtained by polymerization (the total amount of the component A, component B and component C is 100% by weight).
The component A of the polyamide layer is preferably 76 to 84% by weight.
The B component of the polyamide layer is preferably 6 to 14% by weight.

Specific examples of the constitution of the A component, the B component and the C component of the polyamide layer are shown below (however, the total amount of the A component, the B component and the C component is 100% by weight).
(I) The polyamide layer is a copolymer of 50 to 90% by weight of component A and 10 to 50% by weight of the total amount of component B and component C (including three components of component A, component B and component C). Is a polyamide layer made of polyamide.
(II) In the polyamide layer, the A component is 50 to 90% by weight, the B component is 6 to 14% by weight, the rest is the C component, and the total amount of the B component and the C component is 10 to 50% by weight, A polyamide layer made of polyamide obtained by copolymerizing three components of A component, B component and C component is preferred.
(III) The polyamide layer is a copolymer of 76 to 84% by weight of component A and 16 to 24% by weight of the total amount of component B and component C (including three components of component A, component B and component C). The polyamide layer made of polyamide obtained by
(IV) The polyamide layer is 76 to 84% by weight of the A component, 6 to 14% by weight of the B component, the rest is the C component, and the total amount of the B and C components is 16 to 24% by weight, A polyamide layer made of polyamide obtained by copolymerizing three components of A component, B component and C component is preferred.

  The polyamide constituting the polyamide layer can be produced by a known polyamide polymerization method such as melt polymerization, solution polymerization or solid phase polymerization. Production equipment includes known polyamides such as batch reaction kettles, single tank or multi-tank continuous reaction apparatuses, tubular continuous reaction apparatuses, kneading reaction extruders such as uniaxial kneading extruders and biaxial kneading extruders, etc. Manufacturing equipment can be used. As a polymerization method, a known method such as melt polymerization, solution polymerization, or solid phase polymerization can be used, and polymerization can be performed by repeating normal pressure, reduced pressure, and pressure operations. These polymerization methods can be used alone or in appropriate combination.

The film for deep-drawing packaging of the present invention can have a thermoplastic resin layer having heat-fusibility as the innermost layer in addition to the polyamide layer.
As the thermoplastic resin layer having heat-fusibility, it is a layer that can be heat-sealed with a deep-drawn packaging lid material, and it is preferable in terms of production efficiency to keep the heat-sealing temperature as low as possible, and a layer having a low melting point is used. It is preferable.
Examples of the thermoplastic resin layer having heat-fusibility include low-density polyethylene, linear low-density polyethylene, ionomer, ethylene-acrylic acid copolymer, ethylene-vinyl acetate copolymer, and ethylene-acrylic acid ester copolymer. In particular, those having a low melting point such as an ethylene-based resin such as an ethylene-methacrylic acid copolymer can be used.

In the deep-drawing packaging film of the present invention, the polyamide layer and the thermoplastic resin layer may be laminated directly by coextrusion, lamination, or the like, or may be laminated via an adhesive or an adhesive resin layer. Coextrusion is preferred because of its excellent productivity.
The deep-drawing packaging film of the present invention can be produced by a molding method such as T-die molding or air-cooled inflation molding.

The layer structure of the polyamide film of the present invention includes a single polyamide layer, two layers of a polyamide layer and a thermoplastic resin layer having heat-fusibility, polyamide layer / (adhesive or adhesive resin layer) / heat fusion. Three layers of a thermoplastic resin layer having adhesive properties, a polyamide layer and a thermoplastic resin layer having thermal fusion properties, and at least three layers of resin layers other than these layers, a polyamide layer, a thermoplastic resin layer, and There may be mentioned at least four layers of (adhesive or adhesive resin layer) and resin layers other than these layers.
Specifically, polyamide layer / (adhesive or adhesive resin layer) / resin layer, polyamide layer / (adhesive or adhesive resin layer) / resin layer / (adhesive or adhesive resin layer) / heat fusion Resin layer / (adhesive or adhesive resin layer) / polyamide layer / (adhesive or adhesive resin layer) / thermobondable thermoplastic resin layer, etc. The adhesive or the adhesive resin layer can be provided as necessary.

  In the deep-drawn packaging film of the present invention, the other resin layers excluding the polyamide layer and the thermoplastic resin layer having heat-fusibility include low-density polyethylene, linear low-density polyethylene, ionomer, and ethylene-acrylic acid. Polymers, ethylene-vinyl acetate copolymers, ethylene-acrylic acid ester copolymers, ethylene resins such as ethylene-methacrylic acid copolymers, polyolefins such as polypropylene, polyesters, polyvinyl alcohols, and films thereof Layers can be mentioned.

  As the adhesive resin layer, an acid-modified polyolefin resin such as acid-modified polyethylene grafted with at least one monomer selected from an unsaturated carboxylic acid or a derivative thereof can be used.

  The film for deep drawing of the present invention, the polyamide layer constituting this film and the polyamide constituting this layer, the thermoplastic resin layer, the thermoplastic resin constituting this layer, and the like impair the properties of the resulting film and resin. Within the range, heat stabilizer, antioxidant, UV absorber, weathering agent, lubricant, filler, nucleating agent, plasticizer, foaming agent, antiblocking agent, cloud proofing agent, flame retardant, dye, pigment, stabilizer , Coupling agents and the like can be contained.

The thickness of the deep drawn packaging film layer of the present invention is:
(1) In the case of the polyamide layer alone, the polyamide layer is preferably in the range of 10 to 100 μm.
(2) In the case of two layers of a polyamide layer and a thermoplastic resin layer, or three layers or more of a polyamide layer / (adhesive or adhesive resin layer) / thermoplastic resin layer, the polyamide layer is in the range of 2 to 80 μm, The thermoplastic resin layer is preferably in the range of 8 to 120 μm.
The thickness of the adhesive or adhesive resin can be appropriately selected depending on the purpose.

The film for deep drawing packaging of the present invention is excellent in deep drawing formability such as vacuum forming or pressure forming, and a bottom material for deep drawing packaging can be produced by deep drawing.
The bottom material for deep drawing packaging obtained from the film for deep drawing packaging of the present invention can be used for packaging articles such as food such as ham.

  As a deep drawing method for the deep drawing packaging film of the present invention, a known method such as vacuum forming or pressure forming can be used. It consists of deep drawing using a bottom material, filling, and sealing process with a lid material, and a continuous or batch type device can be used. As the deep drawing conditions, it is preferable to select appropriately according to the film thickness and purpose, and the molding temperature is preferably in the range of 60 to 130 ° C.

  Examples will be described below, but the present invention is not limited to these examples.

The measured values shown in the examples and comparative examples are measured by the following method.
1) Measurement of ηr (relative viscosity) of polyamide: According to JIS K6810, 96 wt% concentrated sulfuric acid was used as a solvent at a polyamide concentration of 1 wt / vol%, using an Ubbelohde viscometer at a temperature of 25 ° C. taking measurement.
2) Melting point: Using a DSC210 model manufactured by Seiko Instruments Inc., the sample polyamide was heated to 250 ° C. at a temperature rising rate of 10 ° C./min in a nitrogen gas atmosphere, held at that temperature for 10 minutes, then 10 ° C. / Immediately after cooling to 30 ° C. at a rate of min, the mixture is heated again to 250 ° C. at 10 ° C./min.
3) Haze: Haze is measured using a direct reading haze meter manufactured by Suga Test Instruments Co., Ltd. according to ASTM D-1003.
4) Gloss (Glossiness): Gloss is measured using a digital variable angle glossiness meter manufactured by Suga Test Instruments Co., Ltd. according to ASTM D-523.
5) Puncture strength: Measured under the conditions of a puncture speed of 50 mm / min, 23 ° C., and 50% RH using Tensilon UTM-III-200 manufactured by TOYO BALDWIN in accordance with JAS · P1019.
6) Oxygen permeability: Measured under conditions of 23 ° C. and 0% RH using MOCON-OX-TRAN 2/20 manufactured by Modern Control, in accordance with ASTM D-3985-81.

  Evaluation of haze, gloss, puncture strength, and oxygen permeability is performed using the bottom surface of the deep-drawn film after deep drawing a three-layer unstretched film obtained by air-cooled inflation molding. Deep drawing is performed using a vacuum forming apparatus PLAVAC TV-33 (manufactured by Sanwa Kogyo Co., Ltd.) under the conditions of a deep drawing temperature of 80 ° C., a drawing depth of 20 mm, a preheating time of 120 seconds, and a vacuum degree of 20 Torr.

7) Deep drawability, draw depth (mm): Evaluation of deep drawability and draw depth is performed using a three-layer unstretched film obtained by air-cooled inflation molding.
Judgment is made by observing the grip of the film seal part (chuck) at the time of deep drawing and the presence or absence of uneven drawing of the deeply drawn film. Deep drawing is performed using a vacuum forming apparatus PLAVAC TV-33 type manufactured by Sanwa Kogyo Co., Ltd. under the conditions of a deep drawing temperature of 80 ° C., a preheating time of 120 seconds, and a degree of vacuum of 20 Torr.
The evaluation is indicated by ◎ when the film seal portion is sufficiently gripped and uniform deep drawing is possible: 、, when uniform deep drawing is possible: 、, when deep drawing is possible but unevenness occurs: Δ.
Moreover, let the maximum container height (mm) which does not fracture | rupture at the time of shaping | molding on the said conditions be a drawing depth.

(Polymerization example 1)
A 70 L autoclave was charged with 16.0 kg of ε-caprolactam, 4.0 kg of AH salt aqueous solution (50 wt% aqueous solution), 2.0 kg of 12-aminododecanoic acid and 2.0 kg of distilled water, and the inside of the polymerization tank was replaced with nitrogen. Then, it was sealed and heated up to 180 ° C., and then the temperature in the polymerization vessel was raised to 240 ° C. while adjusting the pressure in the polymerization vessel to 17.5 kgf / cm ² G while stirring. 2 hours after the polymerization temperature reached 240 ° C., the pressure in the polymerization tank was released to normal pressure over about 2 hours. After releasing the pressure, the mixture was polymerized for 1 hr under a nitrogen stream and then subjected to vacuum polymerization for 2 hr. Nitrogen was introduced and the pressure was restored to normal pressure. Then, the stirrer was stopped, and the strand was extracted and pelletized. The polyamide pellets were placed in boiling water, washed with stirring for about 12 hours to extract and remove unreacted monomers, and then dried under reduced pressure at 100 ° C. for 24 hours. The polyamide thus obtained had a relative viscosity of 3.88 and a melting point of 188 ° C. This polyamide is referred to as PA-1.

(Polymerization example 2)
A 70 L autoclave was charged with 16.0 kg of ε-caprolactam, 2.4 kg of an AH salt aqueous solution (50 wt% aqueous solution), 2.8 kg of 12-aminododecanoic acid and 2.8 kg of distilled water. And a polyamide having a relative viscosity of 3.89 and a melting point of 188 ° C. was obtained. This polyamide is referred to as PA-2.

(Polymerization Example 3)
A 70 L autoclave was charged with 16.0 kg of ε-caprolactam and 8.0 kg of an AH salt aqueous solution (50 wt% aqueous solution), and the same procedure as in Polymerization Example 1 was carried out. Polyamide having a relative viscosity of 3.92 and a melting point of 189 ° C. Got. This polyamide is referred to as PA-3.

(Polymerization example 4)
A 70 L autoclave was charged with 16.0 kg of ε-caprolactam, 4.0 kg of 12-aminododecanoic acid and 4.0 kg of distilled water, and the same procedure as in Polymerization Example 1 was carried out. A polyamide at 0 ° C. was obtained. This polyamide is referred to as PA-4.

(Polymerization Example 5)
A 70 L autoclave was charged with 17.0 kg of ε-caprolactam, 6.0 kg of an AH salt aqueous solution (50 wt% aqueous solution) and 1.0 kg of distilled water, and the same procedure as in Polymerization Example 1 was carried out. A polyamide with a melting point of 192 ° C. was obtained. This polyamide is referred to as PA-5.

(Polymerization Example 6)
A 70 L autoclave was charged with 15.0 kg of ε-caprolactam, 5.0 kg of 12-aminododecanoic acid and 4.0 kg of distilled water, and the same procedure as in Polymerization Example 1 was carried out. The relative viscosity was 3.86 and the melting point was 189. A polyamide at 0 ° C. was obtained. This polyamide is referred to as PA-6.

Example 1
Continuously air-cooled inflation molding under the conditions of an ambient temperature of 25 ° C, a resin temperature of 250 ° C, and a blow-up ratio of 1.53, using a three-layer, three-layer co-extrusion air-cooled multi-layer inflation molding machine manufactured by Prabo. Thus, a three-layer film was produced. Using a three-layer, three-layer co-extrusion air-cooled multilayer inflation molding machine (die diameter: 100 mmφ) manufactured by Plavo, PA-1 with 300 ppm of lubricant added to the first layer (outermost layer), the second layer (adhesive resin layer) NF518 (trade name: Admer NF518, acid-modified ethylene / α-olefin copolymer) manufactured by Mitsui Chemicals, F222 (manufactured by Ube Industries, trade name: UBE polyethylene F222, low density) for the third layer (innermost layer) Polyethylene) was continuously air-cooled and blown under the conditions of an ambient temperature of 25 ° C., a resin temperature of 250 ° C., and a blow-up ratio of 1.53, and a total film thickness of 100 μm (first layer: 30 μm, second layer: 5 μm, third Layer: 65 μm) was produced.
Using this film, a vacuum forming device PLAVAC TV-33 type manufactured by Sanwa Kogyo Co., Ltd. was used to create a deep drawing bottom material at a deep drawing temperature of 80 ° C., a preheating time of 120 sec, and a vacuum degree of 20 Torr. The confirmation of the state was confirmed, and the results are shown in Table 1.

(Example 2)
Except for using PA-2 with 300 ppm of lubricant added to the first layer (outermost layer), film forming and deep drawing were performed in the same manner as in Example 1 to confirm the deep drawing state and measure various physical properties. did. The results are shown in Table 1.

(Comparative Examples 1-4)
Film forming and deep drawing are performed in the same manner as in Example 1 except that PA-3, PA-4, PA-5 or PA-6 with 300 ppm of lubricant added to the first layer (outermost layer) is used. The deep drawing state was confirmed and various physical properties were measured. The results are shown in Table 1.

  In Examples 1 and 2 and Comparative Examples 1 to 4, the polyamide used for the first layer (outermost layer) does not contain a nucleating agent.

Claims (3)

A single-layer or multi-layer polyamide film having at least one polyamide layer;
The polyamide layer comprises 76 to 84% by weight of a component selected from (A) ε-caprolactam and ε-aminocaproic acid, (B) a component selected from 12-aminododecanoic acid and ω-laurolactam, and (C) hexamethylene. 16-24% by weight of total amount of diamine and equimolar salt of adipic acid (total amount of B component and C component) (3 components including A component, B component and C component) the amount is 100% by weight in a) to obtain a polyamide,
A film for deep-drawing packaging , wherein the component selected from (B) 12-aminododecanoic acid and ω-laurolactam in the polyamide layer is 6 to 14% by weight . A multilayer polyamide film of two or more layers having at least one polyamide layer and an innermost thermoplastic resin layer having heat-fusibility;
The polyamide layer comprises 76 to 84% by weight of a component selected from (A) ε-caprolactam and ε-aminocaproic acid, (B) a component selected from 12-aminododecanoic acid and ω-laurolactam, and (C) hexamethylene. 16-24% by weight of total amount of diamine and equimolar salt of adipic acid (total amount of B component and C component) (3 components including A component, B component and C component) The amount of which is 100% by weight)
Become
A film for deep-drawing packaging , wherein the component selected from (B) 12-aminododecanoic acid and ω-laurolactam in the polyamide layer is 6 to 14% by weight . A deep-drawing packaging bottom material obtained by deep-drawing the deep-drawing packaging film according to claim 1 or 2 .