JP2001192484A - Film with excellent surface characteristic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a coated film or sheet with the coating film hard to be peeled off even put to improper use compared to conventional products, namely excellent in surface characteristics compared to conventional products. SOLUTION: This method for producing a film or sheet with excellent surface characteristics comprises subjecting a film or sheet to plasma treatment followed by coating and then drying the resultant film or sheet under heating; alternatively, comprises the following practice: the above coated film or sheet is dried under heating while expanding the area thereof by a factor of >=1 both longitudinally and transversely.

Description

DETAILED DESCRIPTION OF THE INVENTION

 [Industrial applications]

The present invention relates to a method for supplying a coating film or sheet having a coating film that is less likely to peel off due to abuse than conventional products and has better surface characteristics than conventional products. [Conventional technology]

Conventionally, unstretched or uniaxially stretched or 2
Performs corona treatment or flame treatment on axially stretched films and sheets, and provides easy adhesion coating, easy printing coating, easy slipping coating, antiblocking coating, antistatic coating, gas barrier coating, water vapor barrier coating, and water resistant coating Abrasion-resistant coating, metal-evaporable coating, metal-oxide-evaporable coating, diamond-like-carbon-easily-evaporable coating, easy-writing coating, anti-fog coating, sol-gel coating, nanocomposite coating Coatings such as coatings and matte coatings have been used to improve the surface properties of films and sheets, but coatings have poor affinity between the film and sheets and coating agents. Surface properties of the film after packaging is not sufficient.

In order to improve the inefficiency of coating, unstretched film extruded from a die is coated and biaxially stretched 2 to 8 times in each of longitudinal and transverse directions by a tenter type simultaneous biaxial stretching machine having a chuck, or The unstretched film extruded from the die is uniaxially stretched 2 to 8 times by a roll in the longitudinal direction, and then stretched 2 to 8 times in the transverse direction by a tenter-type sequential biaxial stretching machine having a chuck, thereby efficiently coating. In-line coating methods have also been implemented. However, the in-line coating method stretches the film or sheet horizontally or vertically and horizontally 2 to 8 times after coating.
As the area of the film increases and the area of the coating film increases, poor adhesion of the coating film, film peeling,
In many cases, a coating film having sufficient performance cannot be obtained because film breakage, pinholes, cracks, crazes, and the like easily occur. [Problems to be solved by the invention]

[0004] The technique of the present invention involves subjecting a plastic film or sheet surface that has not been stretched or transversely uniaxially stretched or longitudinally uniaxially stretched or biaxially stretched to plasma treatment at atmospheric pressure, and then to plasma treatment. For producing a coating film by performing a coating treatment on a coated surface and drying or heat-treating the coated film, and a method for coating an unstretched or longitudinally uniaxially stretched film or sheet and then stretching the film horizontally or vertically and horizontally.
By using a method for producing an axially stretched or biaxially stretched plastic film or sheet, it is possible to obtain a coating film having excellent surface properties that are unlikely to cause poor adhesion of the coating film, film breakage, film peeling, pinholes, cracks, and crazes. Successful.

Unstretched or uniaxially stretched or biaxially stretched films or sheets subjected to plasma treatment and coating are made of polyolefins such as PP and PE, polystyrene,
Polyesters such as polyvinyl chloride, polyvinylidene chloride, ethylene vinyl alcohol copolymer (EVOH), polyvinyl alcohol, PET, PEN, PETG,
It can be manufactured by melting and extruding a thermoplastic such as polyamide such as nylon 6 and MXD6, polycarbonate, polyvinyl acetate and polyacrylate.

[0006] Plasma treatment of unstretched, uniaxially stretched or biaxially stretched films or sheets is desirably performed continuously at atmospheric pressure in order to mass produce commercial coating films. Conventionally, a method of performing plasma processing in a vacuum has been known, but this is a method of performing plasma processing in a vacuum chamber in a batch manner, and cannot mass-produce a coating film continuously.

For the plasma treatment performed at atmospheric pressure, for example, an APT processor manufactured by Sigma Laboratories can be used. A single or mixed plasma of helium, argon, nitrogen, oxygen, nitrous oxide, carbon dioxide, methane, acetylene, propane, ammonia or the like is generated from an atmospheric pressure plasma generating electrode to perform a plasma treatment on the film or sheet surface. By performing atmospheric pressure plasma treatment, polar groups such as carbonyl groups, carboxyl groups, hydroxyl groups, amino groups, etc. are generated on the film or sheet surface in a larger amount than when corona treatment or flame treatment is performed. The degree of surface treatment does not decrease due to a change with time, unlike the degree of treatment when corona treatment or flame treatment is performed.

The coating treatment of the present invention, in which the surface of the unstretched or longitudinally uniaxially stretched plastic film or sheet is subjected to plasma treatment at atmospheric pressure, and then the plasma treated surface is subjected to coating treatment, is easily adhesive. Coating, printable coating, slippery coating, anti-blocking coating, antistatic coating, gas barrier coating, water vapor barrier coating, water resistant coating, abrasion resistant coating, easy metal deposition coating, easy metal oxide deposition Coatings such as a hydrophilic coating, a diamond-like carbon easy-to-deposit coating, an easy-to-write coating, an anti-fog coating, an easy sol-gel coating, an easy nanocomposite coating, and a matte coating. This is a coating process that improves the surface properties of the film or sheet.

The coating treatment in the present invention is performed by applying a coating solution to the surface of a film or sheet that has been subjected to plasma treatment. The composition of the coating solution is an antistatic agent, an antiblocking agent, an easy-to-adhesive, an easy-to-print agent, a slippery agent, an antiblocking agent, a combination of a polymerizable organic monomer and a polymerization catalyst, and / or polyvinyl acetate, polyacrylic Acid, polyacrylate, ethylene vinyl alcohol (EVOH), polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride,
A polymer or copolymer having a functional group such as polystyrene, polyurethane, isocyanate, polycarbonate, polyester, water-soluble polyester, water-soluble polyester urethane, polyamide alone or a mixture thereof,
A solution dissolved in an organic solvent or water or an organic solvent / water mixed solvent, or / and a fine inorganic flat plate such as talc, calcium carbonate, zeolite, silica, or other inorganic powder, montmorillonite, vermiculite, synthetic mica, or tetraethoxy. It is a solution in which an inorganic / organic compound such as silane and tetraisopropoxy zirconium alone or a mixture thereof is mixed.

The surface of the unstretched or longitudinally uniaxially stretched or transversely uniaxially stretched film or sheet is subjected to atmospheric pressure plasma treatment, coated with the above coating liquid, and dried by a method such as hot air drying by a drier to obtain a coating. The resulting film is firmly adhered to the film or sheet surface to obtain a coating film having significantly improved surface properties.

[0011] The surface of an unstretched or longitudinally uniaxially stretched film or sheet is subjected to an atmospheric pressure plasma treatment, coated with the coating solution, and then stretched or stretched in the transverse direction.
According to a method for producing a horizontally uniaxially stretched or biaxially stretched plastic film and sheet stretched in the machine direction,
We succeeded in obtaining a coating film with excellent surface properties, in which poor adhesion of the coating film, film breakage, film peeling, pinholes, cracks, and crazes are unlikely to occur.

In the transverse stretching or the longitudinal and transverse stretching of the present invention, it is desirable that the film is gripped by a chuck with a tenter and the heating and drying and the stretching are simultaneously performed by hot air or / and infrared rays. For this purpose, a heating tenter stretching machine capable of simultaneously stretching in the machine direction and a heating tenter stretching machine capable of stretching in the transverse direction are used.

[0013] A film packaging bag, a paper packaging bag, a paper carton, a film lid material, a container, a bottle, the quality of which has been improved over the conventional product using the coating film of the present invention.
Packaging such as blisters, thermoformed containers, closures,
We can manufacture specially processed synthetic paper, specially processed transparent industrial film, specially processed opaque industrial film, magnetic tape film, magnetic desk film and so on.

Example 1 Polypropylene resin was added to 27
An unstretched polypropylene film having a thickness of 675 μm and a width of 50 cm produced by extruding from a die at a temperature of 0 ° C. and cooling with a chill roll was stretched 4.5 times in a machine direction at a temperature of 140 ° C. by a roll to a length of 150 μm. Atmospheric pressure plasma treatment is performed on the surface of the uniaxially stretched polypropylene film, and a water / isopropyl alcohol solution of polyvinyl alcohol is coated to a thickness of 50 μm by a roll, and the film is stretched 7.5 times in a transverse direction at 160 ° C. by a tenter stretching machine. A 22μ thick biaxially oriented polypropylene film (OPP) coated with polyvinyl alcohol to a thickness of 2μ was manufactured, and the oxygen permeability was measured. 20 [mu] 2 axes oxygen permeability of the stretched polypropylene film had a thickness of 1,500cc ^/ m 2 · 24hrs, but the oxygen transmission rate after coating was 25cc ^/ m 2 · 24hrs. For comparison, a corona treatment was performed instead of the atmospheric pressure plasma treatment, and the same polyvinyl alcohol coating and stretching were performed to produce a 22 μm thick biaxially oriented polypropylene film (OPP) coated with polyvinyl alcohol to a thickness of 2 μm. The transmittance was measured.
5cc ^/ m was 2 · 24hrs.

Example 2 An unstretched nylon film having a thickness of 210 μm and a width of 50 cm, produced by extruding 6 nylon from a die at a temperature of 270 ° C. and cooling with a chill roll, was rolled in a machine direction at a temperature of 60 ° C. The surface of a longitudinally uniaxially stretched nylon film having a thickness of 70 μ stretched by a factor of 5 is subjected to an atmospheric pressure plasma treatment, and a water / isopropyl alcohol solution of a polyester urethane resin is coated to a thickness of 4 μ with a roll, and then 130 ° C. by a tenter stretching machine. In the above, a biaxially stretched nylon film (ONy) having a thickness of 1μ coated with polyester urethane to a thickness of 1μ to produce a 16-μm-thick biaxially stretched nylon film (ONy), and performing aluminum vapor deposition to evaluate the adhesiveness of the aluminum vapor-deposited film with a cellophane tape peeling method. As a result, the aluminum deposited film was hard to peel off. For comparison, a 16 µ thick biaxially stretched nylon film (ONy) coated with the same polyester urethane to a 1 µ thickness by corona treatment instead of atmospheric pressure plasma treatment
Was manufactured and subjected to aluminum vapor deposition, and the adhesiveness of the aluminum vapor-deposited film was measured by a cellophane tape peeling method. The aluminum vapor-deposited film was easily peeled off.

Example 3 Polyethylene terephthalate (PET) was extruded from a die at a temperature of 290 ° C. and cooled by a chill roll.
cm stretched unstretched PET film at a temperature of 85 ° C and stretched 3.5 times with a roll in the machine direction.
The surface of the ET film was subjected to an atmospheric pressure plasma treatment, and a water / isopropyl alcohol solution of a polyester urethane resin was coated to a thickness of 3 μm by a roll, and stretched 4 times in the transverse direction at 125 ° C. by a tenter stretching machine to obtain 0.75 μm. A biaxially-stretched PET film (OPET) having a thickness of 12.75 μm coated with polyester urethane was produced, aluminum was deposited, and the adhesiveness of the aluminum-deposited film was measured by a cellophane peeling method.
The aluminum deposition film was hard to peel off. For comparison, the same polyester urethane was coated to a thickness of 0.75 μm by corona treatment instead of atmospheric pressure plasma treatment.
A biaxially stretched PET film (OPET) of 2.75 μm was manufactured, aluminum was deposited, and the adhesion of the aluminum deposited film was measured by a cellophane peeling method. The aluminum deposited film was easily peeled off.

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Claims (5)

[Claims] 1. A plasma treatment is performed at atmospheric pressure on a plastic film or sheet surface that has not been stretched or stretched uniaxially in the machine direction or uniaxially stretched in the transverse direction or stretched in the machine direction.
After performing a plasma treatment in the air on a coating film or sheet that has been subjected to a coating treatment on a plasma-treated surface and an unstretched or longitudinally uniaxially stretched film or sheet, and coating the plasma-treated surface, A coating film or sheet whose sheet area has been expanded to 1 or more times. 2. The plasma for performing the above-mentioned plasma treatment at atmospheric pressure is an inorganic gas such as oxygen, carbon dioxide, nitrogen, nitrous oxide, helium, argon, or ammonia, or a hydrocarbon such as methane, ethylene, or acetylene;
Single or mixed plasma of organic substances such as alcohols, aldehydes, ketones and esters, or organometallic compounds such as tetraethoxysilane and isopropoxyzirconium. 3. The above coating treatment includes easy-adhesion coating, easy-printing coating, easy-slip coating, anti-blocking coating, antistatic coating, gas barrier coating, water vapor barrier coating, water resistant coating, and abrasion resistance. Coating, easy-to-deposit metal coating, easy-to-deposit metal oxide coating, easy-to-deposit diamond-like carbon coating, easy-to-write coating, anti-fog coating, easy-to-sol gel coating, easy-to-nanocomposite coating, matte coating Coating treatment to improve the surface properties of films or sheets such as. 4. The coating which keeps the area one time after the coating process is subjected to drying or / and heat treatment after the coating process. 5. In the coating treatment for expanding the area one or more times after the coating treatment, the coating is stretched in the vertical and horizontal directions after the coating, or is stretched in the horizontal direction after the coating, and the drying and / or heat treatment is performed by expanding the area.