JP4635680B2 - LAMINATE MANUFACTURING METHOD AND LAMINATE - Google Patents

Description

  The present invention relates to a method for producing a laminate and a laminate produced by the production method.

  A laminate obtained by extrusion coating a polyolefin resin on a substrate such as a polyester resin, a polyamide resin, or paper is used as a packaging material for food, industrial parts, and the like. The packaging material is required to have blocking resistance and slipperiness. For example, the packaging material is formed by extrusion-coating a low-density polyethylene compounded with a surface-hydrophobic anti-blocking agent or an extrusion-coated laminate. A material coated with starch as a blocking agent has been proposed as an extrusion coating laminate excellent in blocking resistance and slipperiness (see Patent Document 1).

JP 2002-225197 A

However, the above-mentioned extrusion coating laminate is not sufficiently satisfactory in terms of blocking resistance and slipperiness, and the laminate is used as a packaging bag by removing the dust-blocking antiblocking agent from the laminate. At this time, an anti-blocking agent may adhere to the object to be packaged or a sealing failure of the packaging bag may occur.
Under such circumstances, the problem to be solved by the present invention is a method for producing a laminate obtained by extrusion coating, and is a laminate excellent in blocking resistance, slipping property and anti-blocking agent desorption resistance. It is providing the manufacturing method of a body, and the laminated body obtained by this manufacturing method.

The first of the present invention is a method for producing a laminate obtained by extrusion-coating a polyolefin resin on a base material. The polyolefin resin is melt-extruded to form a molten film, and an anti-blocking agent is adhered to the roll surface. Arithmetic average of the polyolefin resin side surface, wherein the molten film is disposed between the cooling roll and the substrate, and the anti-blocking agent adhered to the roll surface, the molten film, and the substrate are pressure-bonded by the cooling roll. This relates to a method for producing a laminate having a roughness (Ra) of 2.4 to 12 μm.
The second of the present invention relates to a laminate obtained by the above production method.

  According to the present invention, there is provided a method for producing a laminate obtained by extrusion coating, which is excellent in anti-blocking property, slipperiness and anti-blocking agent desorption resistance, and obtained by the production method. Provided laminates can be provided.

  As the substrate used in the present invention, resin, paper, paperboard, woven fabric, metal foil and the like are used. Examples of the resin include nylon resin, polyester resin, ethylene-vinyl alcohol copolymer, polyvinyl alcohol, polypropylene resin, polyethylene resin, ethylene copolymer, ionomer resin, cellophane, polyvinylidene chloride, polystyrene, Polyvinyl chloride, polycarbonate, polymethyl methacrylate, polyurethane, fluororesin, polyacrylonitrile, polybutene resin, polyimide resin, polyarylate resin, acetylcellulose, etc., these resin single layer films or sheets; laminated films or sheets of these resins They are used as stretched products, coated products, and woven fabrics of these resins. The base material may be a bonded product of these resins and aluminum, iron, paper, or the like. The surface of these resin base materials may be subjected in advance to surface treatment such as corona discharge treatment, plasma treatment, flame treatment or the like, if necessary, or may be printed in advance. The thickness of the substrate is not particularly limited as long as it can be extrusion laminated, and is preferably 1 to 10,000 μm, more preferably 5 to 500 μm.

  The polyolefin resin used in the present invention contains 50% by weight or more of one or more monomer units based on olefins having 2 to 10 carbon atoms such as ethylene, propylene, 1-butene, 1-hexene and the like. Polyethylene resin that is a polymer and contains 50% by weight or more of monomer units based on ethylene, polypropylene resin that is a polymer that contains 50% by weight or more of monomer units based on propylene, and the like can give.

  Examples of the polyethylene resin include ethylene homopolymer, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-1-octene copolymer, ethylene- Ethylene-α-olefin copolymer such as 1-butene-1-hexene copolymer; ethylene-vinyl ester copolymer such as ethylene-vinyl acetate copolymer; ethylene-methyl acrylate copolymer, ethylene-acrylic Examples thereof include ethylene-unsaturated carboxylic acid ester copolymers such as ethyl acetate copolymer, ethylene-butyl acrylate copolymer, ethylene-methyl methacrylate copolymer, and ethylene-ethyl methacrylate copolymer. These are used alone or in combination of two or more. These polyethylene resins are produced by a known method.

  Examples of the polypropylene resin include a propylene homopolymer, a propylene-ethylene copolymer, a propylene-1-butene copolymer, a propylene-1-hexene copolymer, a propylene-ethylene-1-butene copolymer, Examples thereof include propylene-ethylene-1-hexene copolymers, and these are used alone or in combination of two or more. Further, these polypropylene resins are produced by a known method.

  The polyolefin-based resin is preferably a polyethylene-based resin, and the content of the monomer unit based on ethylene in the polyethylene-based resin is 100% by weight of the polyethylene-based resin, preferably 70% by weight or more. Yes, more preferably 80% by weight or more, still more preferably 90% by weight or more.

  As the melt flow rate of the polyolefin resin, in the case of a polyethylene resin, the melt flow rate measured under the conditions of a load of 21.18 N and a temperature of 190 ° C. according to the method defined in JIS K7210-1995 is preferably 1 to 100 g / 10 min, more preferably 1.5-50 g / 10 min. In the case of polypropylene resin, measured under conditions of a load of 21.18 N and a temperature of 230 ° C. according to the method defined in JIS K7210-1995. The melt flow rate is preferably 1 to 100 g / 10 minutes, more preferably 1.5 to 50 g / 10 minutes.

  The polyolefin-based resin may be blended with known additives, for example, an antioxidant, a neutralizing agent, an antistatic agent, an antifogging agent, a lubricant, etc., as required, or may be blended with other resins. .

  Examples of the anti-blocking agent used in the present invention include inorganic anti-blocking agents such as natural silica, synthetic silica, zeolite, calcium carbonate, talc, and glass powder; polymethacrylic acid resin, crosslinked polystyrene resin, and crosslinked polymethyl methacrylate resin. And an organic antiblocking agent such as a crosslinked copolymer of methyl methacrylate and styrene.

  In the production method of the present invention, a polyolefin resin is extrusion coated on a base material, that is, a melted polyolefin resin is coated on the base material in a film form and simultaneously cooled with pressure by a cooling roll. (1) A polyolefin resin is melt extruded to form a molten film, (2) an antiblocking agent is attached to the roll surface of a cooling roll, and (3) the molten film is It arrange | positions between a cooling roll and a base material, (4) The antiblocking agent adhering to the roll surface, this molten film, and this base material are crimped | bonded by this cooling roll.

  The temperature at which the polyolefin-based resin is melt-extruded is preferably 180 ° C. or higher, more preferably 220 ° C. or higher, from the viewpoint of increasing the anti-desorption property of the antiblocking agent. Moreover, from a viewpoint of reducing the smoke generation at the time of melt extrusion and the odor of a film, 340 degreeC or less is preferable and 320 degrees C or less is more preferable. As the melt extrusion apparatus, a known extrusion molding apparatus such as an extruder with a T die can be used.

  Examples of the method of attaching the anti-blocking agent to the roll surface of the cooling roll include a method of spraying the anti-blocking agent slurry in which the anti-blocking agent is dispersed in the liquid onto the roll surface of the cooling roll with a sprayer or the like.

  The weight ratio between the anti-blocking agent and the liquid in the anti-blocking agent slurry is appropriately determined depending on the type of the anti-blocking agent. In general, from the viewpoint of improving the anti-blocking property and slipping property, the anti-blocking agent / liquid is used. (Weight ratio) is preferably 0.01 / 99.9 or more, more preferably 1/99 or more. In addition, the anti-blocking agent / liquid (weight ratio) is preferably 60/40 or less, more preferably 40/60 or less, from the viewpoint of enhancing desorption resistance and reducing spray nozzle clogging. .

  As a liquid used for the anti-blocking agent slurry, water is usually used as a main component. In addition, in order to improve the dispersibility of the antiblocking agent in the liquid, one or more organic solvents may be mixed with water and used. For example, when a cross-linked polymethyl methacrylate resin is used as the antiblocking agent, 15 wt. % Aqueous ethanol solution may be used.

  As a sprayer used for spraying the anti-blocking agent slurry, a spray sprayer is used, and as the spray sprayer, a two-fluid nozzle spray sprayer is preferable. The two-fluid nozzle spray sprayer is usually used at an air pressure of 0.05 to 0.7 MPa and a spray amount of 0.5 to 120 liters / hour.

  The temperature of the roll surface of the cooling roll is usually 5 to 80 ° C. The temperature is preferably 15 ° C. or higher from the viewpoint of improving desorption resistance, blocking resistance, and slipperiness, and preferably 40 ° C. or lower from the viewpoint of improving the roll-off property.

  A known extrusion coating apparatus is used in a method in which a molten film is disposed between a cooling roll and a substrate, and the antiblocking agent attached to the roll surface, the molten film, and the substrate are pressure-bonded by the cooling roll. Moreover, as a pressure which crimps | bonds the antiblocking agent adhering to the roll surface, a molten film, and a base material with a cooling roll, Preferably it is 4.9-24.5 kN / m as a pressing roll linear pressure, More preferably 15.0 to 24.0 kN / m.

  The take-up speed when the anti-blocking agent, the molten film and the substrate attached to the roll surface are pressure-bonded by the cooling roll is usually 15 to 200 m / min.

（Ｌｘ：Ｘ軸方向の基準長さ、 Ｌｙ：Ｙ軸方向の基準長さ） The arithmetic average roughness (Ra) of the polyolefin resin side surface of the laminate obtained by the production method of the present invention is 2.4 to 12 μm. If the value is too small, the anti-blocking property and the slip property may be lowered, and if the value is too large, the desorption resistance may be lowered. The arithmetic average roughness (Ra) is such that the X-axis and the Y-axis are perpendicular to the average surface direction of the roughness curved surface, the Z-axis is taken in the longitudinal magnification direction (direction perpendicular to the average surface), When a roughness curved surface having a reference length in the X-axis direction and a reference length in the Y-axis direction is extracted from the roughness curved surface, and the extracted roughness curved surface is expressed by z = f (x, y), Is a value expressed in μm.

(Lx: reference length in the X-axis direction, Ly: reference length in the Y-axis direction)

  The arithmetic average roughness (Ra) is the temperature at which the polyolefin resin is melt-extruded, the amount of the anti-blocking agent attached to the roll surface on the cooling roll, and the anti-blocking agent attached to the roll surface, the molten film, and the substrate are pressure-bonded. The pressure is adjusted by appropriately changing the pressing roll linear pressure, the take-up speed, the roll surface temperature of the cooling roll, etc.

  The laminate obtained by the production method of the present invention is excellent in anti-blocking property, slipping property and anti-blocking agent desorption resistance, and also has good transparency. Therefore, it is used for various packaging materials such as food packaging materials, pharmaceutical packaging materials, and industrial materials.

Hereinafter, the present invention will be described with reference to examples and comparative examples.
Measurement of physical properties and evaluation in the examples were performed by the following methods.
(1) Density (Unit: kg / m ³ )
It measured according to the method prescribed | regulated to A method among JISK7112-1980. The sample was annealed according to JIS K6760-1995.
(2) Melt flow rate (MFR, unit: g / 10 minutes)
According to the method defined in JIS K7210-1995, the measurement was performed under the conditions of a load of 21.18 N and a temperature of 190 ° C.

(3) Arithmetic mean roughness (Ra, unit: μm)
[Preparation of measurement sample]
After washing the surface of the laminate with acetone and cutting it out to a size of about 4 cm x 2 cm, both sides of the laminate are placed on the slide glass so that the polyethylene resin film surface (the surface to which the anti-blocking agent slurry is pressure-bonded) of the laminate is the measurement surface. A sample for measurement was attached by using a tape.
[Measurement]
Height data was measured under the following measurement conditions using an ultra-deep shape measuring microscope (VK-8510 manufactured by Keyence Corporation, VK-8550 manufactured by Keyence Corporation). In the measurement, it was confirmed that the measurement range in the height direction (DISTANCE) was sufficiently larger than the maximum height of the obtained height data.
<Measurement conditions>
・ RUN MODE: Ultra-deep color ・ VIEW MODE: Light intensity data ・ Objective lens: CF IC EPI Plan 10 ×
(Manufactured by Nikon Corporation, magnification 10 times, numerical aperture 0.3, working distance 16.5 mm)
・ Optical zoom: x1
・ Digital zoom: x1
Measurement area: 1.67 mm ² (1.49 mm (X axis) x 1.12 mm (Y axis))
-Number of pixels in the measurement area: 1024 pixels (X axis) x 768 pixels (Y axis)
・ DISTANCE: 65μm
・ PITCH: 0.5μm
[Calculation of arithmetic mean roughness]
Ra of the height data obtained by the measurement was obtained by the “surface roughness” measurement function of the analysis software (VK shape analysis application VK-H1W Ver.1.06 manufactured by Keyence Corporation). Ra was an average of three times.

(4) Sliding property (dynamic friction coefficient μk)
According to JIS K7125-1987, the dynamic friction coefficient between the polyethylene resin film surfaces (surfaces to which the anti-blocking agent slurry was pressure-bonded) of the laminate was measured. The smaller this value, the better the slipperiness.
(5) Blocking resistance (unit: g / 100 cm ² )
The polyethylene resin film surface (surface sprayed with the anti-blocking agent slurry) of the two laminates cut into 10 cm × 10 cm and the substrate surface are overlapped, and the condition is adjusted for 7 days at a temperature of 40 ° C. under a load of 40 g / cm 2. did. The laminated body was peeled in the vertical direction (without applying a shearing force) at a peeling load rate of 20 g / min using a Mackenzie blocking tester (manufactured by Shimadzu Corporation) in an atmosphere of a temperature of 23 ° C. and a humidity of 50%. The load required to make it go was measured. The smaller this value, the better the anti-blocking property.
(6) Desorption resistance The polyethylene resin film surface of the laminate (the surface to which the anti-blocking agent slurry was pressure-bonded) was rubbed with a finger, and the following evaluation was performed.
A: The anti-blocking agent does not adhere to the finger at all.
○: The anti-blocking agent hardly adheres to the finger.
Δ: The anti-blocking agent slightly adheres to the finger.
X: An anti-blocking agent adheres to a finger.
(7) Transparency (Haze, unit:%)
Haze was measured according to ASTM D1003. The smaller this value, the better the transparency.

Example 1
A polyethylene resin [Sumikasen L705 (MFR = 7 g / min, density = 919 kg / m ³ ) manufactured by Sumitomo Chemical Co., Ltd.] is melt-extruded from a T-die with a φ65 mm extruder to form a molten film, and a roll of a cooling roll On the surface, using a small spray gun [Anest Iwata Co., Ltd. W-100-152S], starting from the center of the cooling roll (diameter 600 mm) from the position of 800 mm vertically upward and 300 mm in the horizontal anti-T die direction, Toward the center of the cooling roll, inorganic anti-blocking agent slurry [inorganic anti-blocking agent (manufactured by Mizusawa Chemical Co., Ltd., synthetic aluminosilicate anti-blocking agent JC-70 (particle size = 7.0 μm)) / water = 33 / 67 (weight ratio)] was sprayed. Next, the melt film is extrusion coated on the surface of the base material [biaxially stretched polyethylene terephthalate film (Toyobo Co., Ltd., Toyobo Ester E5100), thickness = 16 μm], so that the melt film is on the cooling roll side, The base material and the molten film were pressure-bonded with a cooling roll and a nip roll at a pressing roll linear pressure of 19.6 kN / m to obtain a laminate. In the processing of the laminated body, the temperature of the molten film immediately below the die is 300 ° C., the air gap is 150 mm, the film width is 500 mm, the coating thickness of the molten film is 30 μm, the take-up speed is 20 m / min. Ra was 9.0 μm. Table 1 shows the physical property evaluation results of the obtained laminate.

Example 2
A laminate was obtained in the same manner as in Example 1 except that the take-up speed was 40 m / min. Ra of the obtained laminated body was 3.9 micrometers. Table 1 shows the physical property evaluation results of the obtained laminate.

Example 3
Instead of inorganic anti-blocking agent slurry, organic anti-blocking agent slurry [Organic anti-blocking agent (Nippon Shokubai Co., Ltd., spherical fine particles Eposta MA1010 (polymethyl methacrylate cross-linked product, particle size = 9.7 μm)) / Water / ethanol = 33/56/11 (weight ratio)] was performed in the same manner as in Example 1 to obtain a laminate. Ra of the obtained laminated body was 4.8 micrometers. Table 1 shows the physical property evaluation results of the obtained laminate.

Comparative Example 1
A laminate was obtained in the same manner as in Example 1 except that the take-up speed was 10 m / min. Ra of the obtained laminated body was 14.8 micrometers. Table 2 shows the physical property evaluation results of the obtained laminate.

Comparative Example 2
A laminate was obtained in the same manner as in Example 1 except that the take-up speed was 80 m / min. Ra of the obtained laminated body was 0.97 micrometer. Table 2 shows the physical property evaluation results of the obtained laminate.

Comparative Example 3
A laminate was obtained in the same manner as in Example 3 except that the take-up speed was 60 m / min. Ra of the obtained laminated body was 0.80 micrometer. Table 2 shows the physical property evaluation results of the obtained laminate.

Comparative Example 4
A laminate was obtained in the same manner as in Example 1 except that the inorganic antiblocking agent slurry was not sprayed and the take-up speed was 80 m / min. Ra of the obtained laminated body was 0.15 micrometer. Table 3 shows the physical property evaluation results of the obtained laminate.

Comparative Example 5
10 parts by weight of an inorganic anti-blocking agent [Synthetic aluminosilicate anti-blocking agent JC-50 (particle size = 5.3 μm) manufactured by Mizusawa Chemical Co., Ltd.] and a polyethylene resin [Sumikasen E FV402 (MFR manufactured by Sumitomo Chemical Co., Ltd.) = 4 g / min, density = 915 kg / m ³ )] 90 parts by weight was melt kneaded using a Banbury mixer to prepare an anti-blocking agent master batch having an inorganic anti-blocking agent concentration of 10% by weight.
Next, a laminate was prepared in the same manner as in Comparative Example 4 except that a mixture of 90 parts by weight of a polyethylene resin [Sumikasen L705 manufactured by Sumitomo Chemical Co., Ltd.] and 10 parts by weight of the anti-blocking agent master batch was used. Obtained. Ra of the obtained laminated body was 0.56 micrometer. Table 3 shows the physical property evaluation results of the obtained laminate.

Claims (5)

  A method for producing a laminate by extrusion coating a polyolefin resin on a base material, comprising: a cooling roll in which a polyolefin resin is melt-extruded to form a molten film, and an anti-blocking agent attached to the roll surface; and the base material The molten film is placed between the anti-blocking agent attached to the roll surface, the molten film, and the base material, and the arithmetic average roughness (Ra) of the polyolefin resin side surface is 2 The manufacturing method of the laminated body which is 4-12 micrometers.   The manufacturing method of the laminated body of Claim 1 whose cooling roll which made the anti-blocking agent adhere to the roll surface is a cooling roll formed by spraying an anti-blocking agent slurry on the roll surface. The weight ratio (anti-blocking agent / liquid) of the anti-blocking agent and the liquid in the anti-blocking agent slurry is 1/99 to 60/40 , and the liquid is mainly composed of water. Production method.   A polyolefin-based resin is melt-extruded at a temperature of 180 to 340 ° C. to form a molten film, and the anti-blocking agent attached to the roll surface, the molten film, and the substrate are subjected to a pressing roll linear pressure of 4.9 to 24.5 kN / m. The manufacturing method of the laminated body in any one of Claims 1-3 crimped by.   The polyolefin resin is a polyethylene resin, and the melt flow rate of the polyethylene resin measured under the conditions of a load of 21.18 N and a temperature of 190 ° C. according to the method defined in JIS K7210-1995 is 1 to 100 g / 10. The method for producing a laminate according to any one of claims 1 to 4, wherein the laminate is a minute.