JPS6213337A - Coated polyolefin group film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a polyolefin film coated with an acrylic polymer having excellent oil resistance, and more specifically to a coating suitable for packaging articles containing oil. 〇 Regarding polyolefin films (Conventional technology) Conventional polyolefin films are characterized by their transparency.

Because it has the characteristics of flexibility and low cost, it can be used as it is or by two-wheel stretching, or for the purpose of adding properties such as heat sealability and gas barrier properties to the surface.
For example, an anchor coating layer is first provided on the corona-treated surface, then a top coating layer such as polyvinylidene chloride resin is coated on top of the anchor coating layer, and then a heat-adhesive film is further laminated on the back side, which is commonly used as a packaging material. There is.

The above-mentioned anchor coating layer was used for the purpose of increasing the adhesion between the base polyolefin film and the top coating. Until now, there has been no known film that provides oil resistance to the anchor coating layer and has thermal adhesive properties by adding a top coating layer, as in the present invention.

(Problems to be Solved by the Present Invention) However, Al
Since lllf has the property of swelling when it absorbs oils such as mineral oils, benzene, and aromatic hydrocarbons such as toluene, packaging materials using these polyolefin films can be used to package articles containing the above oils. For example, if a seal is wrapped inside wrapping paper printed using printing ink containing the above-mentioned oils, or if the package is left in an atmosphere containing vapors of the above-mentioned oils. Even a polyolefin film having a polyvinylidene chloride layer on its surface absorbs oil and wrinkles appear on its surface.

It has the disadvantage that it significantly reduces the commercial value of the packaged product.

On the other hand, in an attempt to improve these oil resistance defects, 1
For example, Japanese Patent Application Laid-Open No. 57-20822.

Proposals such as fF Publication No. 57-20846 have been made.

The former relates to improving the oil resistance of polyolefin films, and the latter relates to improving the oil resistance of polyolefin films coated with polychlorination and = 17dene resin. This is intended to offset the residual heat shrinkage of the base material in the vicinity, but the room temperature is summer.

Because it fluctuates depending on the winter season, it is not possible to obtain a stable effect throughout the year.

(Means for Solving the Problems) In order to solve the above-mentioned drawbacks caused by oil absorption of polyolefin films, the inventors of the present invention have made intensive studies and found that a specific acrylic, lyl-based They found that by providing a layer containing a polymer, oil components do not pass through this acrylic polymer layer and are not absorbed by the polyolefin film layer, and thus completed the present invention.

Namely, the present invention provides a polyolefin film containing at least 40% by weight of an acrylic polymer having a secondary transition temperature (Tg) of 60-110°C and an average molecular weight of 10,000 to 800,000 on at least one side of the polyolefin film. The present invention relates to a coated polyolefin film with excellent oil resistance, which is characterized by being provided with a coalescing layer.

The polyolefin film used in the present invention is not particularly limited, and includes polypropylene, polyethylene, polybutylene, ionomers, and mixtures thereof;
Examples include a cast film made of a copolymer and a biaxially stretched film.

Furthermore, the acrylic polymer used in the present invention has a secondary transition point of 60
~110°C and an average molecular weight of 10,000 to 800,000 are suitable, and those with a secondary transition point of fF of 70 to 105°C and an average molecular weight of 40,000 to 200,000 are particularly preferable. 6
If it is below 0℃, the oil absorption and oil permeability will be high, and the oil shielding effect on the polyolefin film layer will be insufficient.If it exceeds 110℃, the solubility in the coating solvent will decrease significantly and the The flexibility of the coating film deteriorates,
When bent, pinholes and cracks are likely to form, which is undesirable as the oil shielding effect decreases.In addition, those with an average molecular weight of less than 10,000 are similarly insufficient in oil resistance (oil shielding effect). If it exceeds 300,000, the solubility in the coating solvent decreases, and even if it can be dissolved, the solution viscosity is high, making it impractical.

Examples of monomers constituting the acrylic polymer used in the present invention include methyl methacrylate.

Ethyl methacrylate, isopropyl methacrylate.

n-butyl methacrylate, isobutyl methacrylate, amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, methyl acrylate, ethyl acrylate, isopropyl acrylate, butyl acrylate, amyl acrylate, One or two types selected from the group consisting of methacrylic acid such as n-hexyl acrylate and 2-ethylhexyl acrylate, and acrylic acid monomers consisting of acrylic acid alkyl esters, acrylic acid, methacrylic acid, glycidyl methacrylate, etc. The above are the essential ingredients, and in addition, 39 mol of maleic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, vinylidene chloride, and acrylamide.
The acrylic polymer layer of the present invention may be contained within a range of ◇ or less. Methods for providing the acrylic polymer layer of the present invention include, but are not limited to, the following methods. ◇ ■ Used alone. ■It is used in combination with a component containing an isocyanate group in order to improve adhesion to polyolefin films. (2) A component containing a hydroxyl group and a component containing an isocyanate group are mixed together and used. ■To further enhance the oil resistance effect, polyvinylidene chloride resin and polyvinyl chloride resin are used in combination.

When the acrylic polymer of the present invention is used in combination with other components, the acrylic polymer preferably contains 40% by weight or more. If the content of the acrylic polymer is less than 40% by weight, the effect on oil resistance will be insufficient, and it will not provide the polyolefin film with properties such as heat sealing properties, gas barrier properties, sliding properties, and packaging suitability. In order to achieve this, it is possible to further provide a coating of polyvinylidene chloride resin, chlorinated polypropylene resin, etc. on the surface of the acrylic polymer layer, if desired.

Next, a method for producing the coated polyolefin film of the present invention will be explained.

After subjecting one or both sides of the polyolefin film to surface treatment such as corona treatment if necessary, the acrylic polymer of the present invention is dissolved in a mixed solvent suitable for dissolving the resin used in the present invention, such as toluene or ethyl acetate. 0.1 to 1 in terms of solid content per side. Apply it so that it becomes Ofed, 90-10
Dry at 0°C to obtain a coated polyolefin film.

The method for applying the acrylic polymer of the present invention is as follows.

Gravure roll, reverse roll, Meyer bar.

Dip method etc. can be used. Furthermore, heat sealability,
In order to provide packaging suitability such as gas barrier properties, when applying polyvinylidene chloride resin emulsion subsequently, apply 1.5 to 3 seams on one side using an air knife method and dry at 90 to 100''C for 10 seconds. By doing so, a coated polyolefin film can be produced.

In addition, the polyvinylidene chloride coating material may be used in combination with other compounding materials 2, such as anti-blocking agents such as silica, lubricants such as paraffin wax, and anionic, cationic, or nonionic antistatic agents, using a conventional method. . When used in combination, packaging suitability can be significantly increased and it is effective.□ The film of the present invention can be applied not only to cosmetic surfaces as described above, but also to packaging all items containing two oil-based substances. be able to.

(Example) The present invention will be specifically explained below using an example, but is not limited thereto. The method for measuring the physical properties of the film exemplified in the Examples is as follows.

(1) Prepare two test pieces of oil resistance 6cn x 6cjn, and apply 20q of OP varnish (manufactured by Toyo Ink, 6P, containing 20% mineral oil of 260 to 280°C) in a circular shape (8 pieces φ) on one test surface. Place another test surface on top of it and make sure it adheres well.
Sandwich it between 3fi thick glass plates measuring ay+x10m and put it in an airtight container.

It was stored at 85°C for 3 days.

Judgment criteria ○: No amorphous wrinkles were observed.

Δ: 11 // A slight occurrence occurred.

×:〃〃 Numerous occurrences were occurring. ρ) Oil absorption rate OP varnish was placed at 40℃ and 6c! nX6c! The double-sided coated test piece of No. 11 was hung and evaluated based on the weight increase rate after being left for 4 days.

Oil absorption rate (weight %) = (8) Actual packaging test on cosmetic printed surface The outer packaging film of commercially available cosmetic artist confectionery was removed, and instead it was heavily wrapped with test film and left at 35°C for 2 weeks. After that, the test film surface was judged as follows depending on the wrinkle occurrence state.

Judgment criteria ○: No irregular wrinkles were observed.

Δ:〃〃〃〃It occurred a little.

×: There were countless occurrences.

(4) Heat seal strength: The coated surface of a 151 m wide test piece was sealed with a bar sealer (sealing pressure IKF/!, sealing time 0) at 120°C.
．． 5 seconds) to heat seal, Tensilon (tensile speed 1
00111I/In1n, chart speed 800W
/m1n), and the heat seal strength was measured by peeling at 90°. A 20μ biaxially stretched polypropylene film of Example 1 was coated with a 10% solution (ethyl acetate, toluene mixture Q) of an anchor coating agent having the composition shown in Table 1 using a gravure roll. After that, dry it with hot air at 90℃ for 10 seconds,
A film with a coating amount of 0.8 seams was formed. Further, on top of this, a top coating agent having the following composition with a solid content concentration of 40% by weight was applied using a Mayer bar so that 7f5@8 sheets were coated, and the same operation was repeated. A biaxially stretched polypropylene film coated on both sides was obtained.

Top coating agent formulation: 100 parts polyvinylidene chloride resin emulsion (heat seal type, solid content 50 yen) Silica (particle size 8 μ, solid content 101) 0.25 parts wax emulsion (rn, p, 60 ” C, 4.0 parts (solid content 80%) 1.0 parts phosphate ester antistatic agent (solid content 20%) The properties of the biaxially oriented polypropylene film coated on both sides with each of the obtained formulations were as follows. As shown in the table, it had excellent oil resistance and H88 packaging suitability. A non-stretched polyglopylene film ?r4 was coated with a polyvinylidene chloride resin and a polyvinylidene chloride resin emulsion.The properties of the obtained film were as follows.
As shown in the table, oil resistance and H88 packaging suitability were good.

Comparative Example 1 Coating was carried out in the same manner as in Example 1, except that an acrylic copolymer having a secondary transition point of 20°C and an average molecular weight of 70,000 was used as the anchor coating agent.

Obtain a coated biaxially oriented polypropylene film. As shown in Table 1, the properties of the obtained film were poor in durability.

Comparative Example 2 90% water by weight without using acrylic polymer as anchor coating agent! ! ! Ingredients containing groups (Toyobo,
A coated biaxially oriented polypropylene film was obtained by coating in the same manner as in Example 1, except that a reactive component containing Vylon 308) and an isocyanate group (Nippon Polyurethane Co., Ltd., KONE 1 to L) was used. As shown in Table 1, the obtained film had poor oil resistance.

Comparative Example 3 A coated biaxially stretched polypropylene film was obtained in exactly the same manner as in Example 2, except that the acrylic copolymer used as the anchor coating agent had a low secondary transition point. The properties of the obtained film are as shown in Table 1, with an oil resistance of 4.
- It wasn't even a minute.

[Left below] Jar IMMA: Methyl methacrylate, MA methyl diacrylate, BA butyl diacrylate.

MMA/MA: Methyl methacrylate/methyl acrylate copolymer.

Hata 2 Coronate L: component having an incyanate group (
(manufactured by Nippon Polyurethane ■) 0 *3 Byan SO8: Polymer with a water dispersion group (manufactured by Toyobo Co., Ltd.).

Jar 4 Denka vinyl 5 loooL'r3: PVC polymer (manufactured by Denki Kagaku Co., Ltd.).

Claims (1)

[Claims] A polymer layer containing at least 40% by weight of an acrylic polymer having a secondary transition point of 60° C. to 110° C. and an average molecular weight of 10,000 to 300,000 is provided on at least one side of the polyolefin film. A coated polyolefin film with excellent oil resistance.