KR100443335B1 - High-interruptive composition and coating film manufactured therewith - Google Patents

Abstract

The present invention is environment-friendly and oxygen / water vapor barrier properties is a degree of saponification of 50-99 mol% and a degree of polymerization is 100-5000 is 70 to 99.9% by weight of polyvinyl alcohol and 10 ^-2 to 10 to Excellent ⁴ nanometers (nm) in size The present invention relates to a high barrier coating liquid and a coating film prepared using the same, comprising 100 to 1900 parts by weight of a solvent, based on 100 parts by weight of solids, which is composed of 0.1 to 30% by weight of clay having a diameter of The coating film has excellent oxygen / water vapor barrier properties, and it has the advantage of eliminating the dioxin problem of chlorine-based coating materials because of the dispersion of clay, an environmentally friendly material that does not generate harmful substances when incinerated. The lowering of barrier properties due to humidity, a fatal drawback of alcohol, has been improved.

Description

High-interruptive composition and coating film manufactured therewith}

The present invention relates to a high barrier coating liquid and a coating film using the same, and more particularly, a high barrier coating liquid in which clay particles having a size of 10 ^-2 to 10 ⁴ nanometers (nm) are dispersed in polyvinyl alcohol, and prepared using the same. The present invention relates to a coating film having excellent oxygen / water vapor barrier properties and markedly improved barrier weakness due to humidity.

Conventionally, high barrier coating liquids and coating films are polyvinylidene chloride (PVDC) coated products, and development of alternative materials has been urgently needed due to environmental problems caused by dioxins generated during incineration due to the chlorine-based properties. .

Accordingly, polyvinyl alcohols were used as coating materials to replace the polyvinylidene chlorides, but they showed excellent barrier properties, but the barrier properties deteriorated with increasing humidity.

The present invention has been made in order to solve the problems as described above, and an object of the present invention is to provide a coating solution and a coating film which is significantly improved compared to pure polyvinyl alcohol by a weakening of the external environment such as humidity.

Another object of the present invention is to provide a coating solution and a coating film which are environmentally friendly and excellent in oxygen / water vapor barrier properties.

Still another object of the present invention is to provide a coating film having high barrier properties while maintaining the optical properties inherent in the base film.

The above object of the present invention is achieved by providing a coating liquid based on polyvinyl alcohol having excellent barrier properties and nanometer-sized clay dispersed therein and a film coated on one or both sides of various substrate films. Not only is it environmentally friendly, it also serves to supplement and improve the barrier property of polyvinyl alcohol.

Figure 1a, 1b is a cross-sectional view showing an embodiment of the coating film of the present invention,

Figure 2a, 2b is a cross-sectional view showing another embodiment of the coating film of the present invention,

3 is a viscosity change table according to the solid content of the coating solution of the present invention,

4 is a viscosity change table according to the amount of clay added in the coating solution of the present invention,

5 is an oxygen permeability change table according to the clay addition amount of the coating film of the present invention,

6 is a water vapor permeability change table according to the clay addition amount of the coating film of the present invention,

Figure 7 is the oxygen permeability change table according to the coating film thickness of the coating film of the present invention,

8 is a water vapor transmission rate change table according to the coating film thickness of the coating film of the present invention,

9 is an oxygen permeability change table according to the relative humidity of the coating film and the pure polyvinyl alcohol coating film of the present invention.

The present invention is made from 70 to 99.9% by weight of polyvinyl alcohol having a degree of saponification of 50 to 99 mol% and a polymerization degree of 100 to 5000 and from 0.1 to 30% by weight of clay having a diameter of 10 ^-2 to 10 ⁴ nanometers (nm). It relates to a high barrier coating liquid comprising 100 to 1900 parts by weight of solvent with respect to 100 parts by weight of solids constituted.

The high barrier coating liquid of the present invention used 70 to 99.9 wt% of polyvinyl alcohol (PVA) as a main component of solid content, and it was nanometer sized as an auxiliary material to further improve the barrier property and prevent the barrier to humidity. 0.1 to 30% by weight of natural mineral clay was used.

The polyvinyl alcohol used for preparing the coating solution preferably has a degree of saponication of 50 to 99 mol% (mol%) and a polymerization degree of 100 to 5000. Polyvinyl alcohol having a saponification degree outside the above range has a problem that does not dissolve in a solvent such as water when preparing a coating solution, in the case of polyvinyl alcohol having a polymerization degree outside the range of 100 to 5000, the strength of the film is weak or the viscosity of the coating solution There is a problem that the rise is difficult to manufacture the coating liquid.

The clay used as an auxiliary material of the coating solution may be selected from one or more selected from the group consisting of kaolinite, illite, clay-mica, smectite, and chlorite. Without limitation, any clay having a diameter of 10 ⁻² to 10 ⁴ nanometers (nm) may be used.

If the representative of the type of clay used in the practice of the present invention to introduce a bentonite (bentonite) is a kind of metamorphic rock represented by the Smectite group clay mineral. In the case of bentonite, the chemical name is called hydrated sodium calcium aluminum silicate. The bentonite may be divided into so-called "dioctahedral type" and "trioctahedral type" according to the filling of the cation sites in the octahedral structure and the difference in the interlayer cation composition.

Montmorillonite, Smectite Sodium montmorillonite, Sodium bentonite; Wyoming bentonite (US), Swelling bentonite (Western bentonite (US)}, Sodium-activated bentonite (Bentonitte (UK)}, Sodium-exchange Bentonite {Sodium-exchanged bentonite; Synthetic bentonite}, Calcium montmorillonite; Calcium bentonite Mississippi bentonite (US), Sub-bentonite {Sub-bentonite; Texas (Texas bentonite (US)), Magnesium montmorillonite (Saponite & Armargosite), Potassium montmorillonite (Metabentonite), and lithium montmorite It may also be called Lilonite (Hithite).

In the case of mica, there are synthetic mica in which -OH group is substituted with fluorine (F).

In the preparation of the coating solution of the present invention, as a solvent of the solid component composed of polyvinyl alcohol and clay, water, ethyl alcohol, ortho-chlorophenol having excellent solubility and dispersibility in both polyvinyl alcohol and clay (ortho) -chlorophenol (OCP), ethylene glycol (EG), dimethyl-sulfoxide (DMSO), phenol and the like are preferable.

In addition, polyvinyl alcohol and clay constituting a solid content in the coating liquid is preferably blended at 70 to 99.9% by weight and 0.1 to 30% by weight. If the amount of clay is added less than the above range, the effect of the addition of clay is insignificant, and if more is added, the efficiency is low in terms of economic efficiency compared to the effect.

In preparing a coating solution using the above-described polyvinyl alcohol, clay, and solvent, 100 parts by weight of solid content (polyvinyl alcohol and clay) and 100 to 1900 parts by weight of a solvent were mixed under appropriate temperature conditions (10 to 200 ° C).

In the case of the coating liquid outside the above range, it is difficult to control the thickness of the coating film due to too low viscosity, or the coating film of the coating film is subject to the excessive viscosity.

On the other hand, in the preparation of the coating liquid of the present invention, an anti-blocking agent, an antistatic agent, a slip agent, or the like may be added within a range that does not degrade the physical properties of the film after coating. Known ones are not particularly limited and may be variously used.

The invention also comprises 70 to 99.9 weight percent polyvinyl alcohol having a degree of saponification of 50 to 99 mol% and a polymerization degree of 100 to 5000 and 0.1 to 30 weight percent of clay having a diameter of 10 ⁻² to 10 ⁴ nanometers in size. The present invention relates to a high barrier coating film in which a coating liquid comprising 100 to 1900 parts by weight of solvent is coated with a thickness of 0.5 to 10 μm on one or both sides of a base film.

As shown in FIGS. 1A and 1B, the coating film is formed by stacking the coating layer 30 on one surface of the base film 10 or by stacking the coating layer 30 on both sides of the base film 10.

Coating materials for applying the coating liquid include biaxially stretched polypropylene (BOPP) film, nylon (nylon) film, polyethylene (PE) film, polyester (poly-ethylene terephtalate (PET) film) Both poly-propylene (PP) films can be used and can be applied to both stretched and unstretched films according to the manufacturing method.

In the present invention, the coating method is a conventional method, such as direct gravure (Direct Gravure), a comma (Comma), the reverse (reverse) method and the like is used by hot air drying so that the coating film thickness is approximately 0.5 ~ 10μ.

In the coating thickness outside the above range, the improvement of physical properties is insufficient or more than necessary, so it is adjusted to the above range in consideration of economical efficiency.

In addition, in the production of the coating film of the present invention, a general adhesive primer used for the coating film, such as a polyurethane (PU) -based adhesive in order to improve the bonding strength of the coating liquid and the base film, between the base film and the coating film It can apply | coat in thickness of 0.3-5 micrometers previously.

That is, the process of applying the coating liquid of the present invention to the base film may be made of a process of first applying the primer to the base film and then drying and a continuous process of applying and drying the coating solution, the primer application and drying process It may be omitted depending on the base film.

2A and 2B, the coating film prepared as described above is formed by sequentially stacking the primer layer 20 and the coating layer 30 on one surface of the base film 10, or primers on both sides of the base film 10. The layer 20 and the coating layer 30 are sequentially stacked.

In the coating film of the present invention, there is a difference in oxygen / water vapor permeability according to the mixing ratio of the polyvinyl alcohol and clay constituting the coating liquid, coating thickness, etc., and the change in barrier properties according to humidity is also wrong. The coating film of the present invention is characterized in that the oxygen permeability is 0.01 ~ 150cc / ㎡ / day (varies according to the relative humidity), water vapor permeability is 4 ~ 150cc / ㎡ / day (changes according to the relative humidity).

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

Example 1

1. 95 g of polyvinyl alcohol having a degree of saponification of about 85 mol% (mol%) and a degree of polymerization of about 1000, and Sumecton SA of Kunimine Corp., a synthetic sumectite as clay. ) 5 g.

2. A solid solution comprising 100 g of polyvinyl alcohol and clay, 1 g of synthetic silica anti-blocking agent, and 1 g of amine antistatic agent were added to 900 g of water, which was a solvent, and stirred at a temperature of 80 ° C. for at least 2 hours to prepare a coating solution. .

Examples 2-5

A coating solution was prepared in the same manner as in Example 1 except that polyvinyl alcohol had a saponification degree of 50, 80, 90, and 100 mol% (mol%), respectively.

Examples 6-9

A coating solution was prepared in the same manner as in Example 1 except that polyvinyl alcohol had a polymerization degree of 100, 500, 2000, or 5000, respectively.

Experimental Example 1

Table 1 shows the tendency of solubility in water according to saponification degree and degree of polymerization of polyvinyl alcohol of the coating solution prepared according to Examples 1 to 9.

Solubility in water according to saponification and degree of polymerization of polyvinyl alcohol division Degree of polymerization Sword 100-499 500-1999 2000 ~ 5000 51-79 80-90 91-99 Melting castle increase increase decrease increase increase decrease Aqueous solution decrease decrease increase decrease decrease increase

As a result of the experiment, the saponification degree of polyvinyl alcohol constituting the coating liquid was 80-90 mol%, and the degree of solubility was relatively high when the degree of polymerization was 500-2000. gave.

This shows that polyvinyl alcohol having a degree of saponification of 50 to 99 mol% and a degree of polymerization of 100 to 5000 can be used as a control of temperature conditions in the preparation of a coating solution using water as a solvent.

Examples 10-13

A coating solution was prepared in the same manner as in Example 1 except that the ratios of solids (polyvinyl alcohol and clay) of the coating solution and water as solvents were 12: 88, 15: 85, 18: 82, and 20: 80, respectively.

Experimental Example 2

The viscosity according to the solid content weight percent of the coating solution prepared in Examples 1 and 10 to 13 is measured and shown in FIG.

At this time, the viscosity of the coating solution was measured by dissolving each sample in ortho-chlorophenol at 100 ° C and then using a Ubbelohde viscosity tube at 30 ° C.

As a result of the experiment, as the solid content of the coating solution was increased, the viscosity of the coating solution was increased, and the composition ratio of the solid content of the coating solution and the solvent according to the viscosity of the desired coating solution can be selected.

Therefore, the coating solution of the present invention can be coated on the substrate by varying the coating method (gravure, comma, reverse) according to the increase in viscosity due to the increase in solid content.

Examples 14-20

A coating solution was prepared in the same manner as in Example 1 except that the mixing ratio of polyvinyl alcohol and clay was 99: 1, 97: 3, 92: 8, 90:10, 85:15, 80:20, 70:30, respectively.

Experimental Example 3

The viscosity of the coating solution prepared according to Example 1 and Examples 14 to 20 was measured by the same method as Experimental Example 2, and is shown in FIG. 4.

As a result of the experiment, the viscosity of the coating solution increased as the clay content increased. In consideration of workability, polyvinyl alcohol and clay were preferably blended at 70 to 99.9 wt% and 0.1 to 30 wt%.

Examples 21-25

A coating solution was prepared in the same manner as in Example 1 except that ethyl alcohol, ortho-chlorophenol (OCP), ethylene glycol (EG), and dimethyl sulfoxide were used without using water as a solvent. Seed (dimethyl-sulfuroxide (DMSO), phenol (phenol) was used.

Experimental Example 4

In Examples 1 and 21 to 25, solubility and dispersibility of solid content (polyvinyl alcohol, clay) in various solvents were measured and shown in Table 2.

Solubility and dispersibility in various solvents division water Ethyl alcohol OCP EG DMSO phenol Solubility ◎ ○ ○ ● ● ● -Visual inspection for sediment / float ◎: Excellent solubility / dispersibility ●: Good solubility / dispersibility ○: Good solubility / dispersibility

In the present invention, in addition to the solvent, solvents such as methyl alcohol and DTA which are soluble in both solids may also be used. Such solvent selection may be variously selected in consideration of viscosity / drying property and harmfulness of the coating solution.

Example 26

A coating solution was prepared in the same manner as in Example 1, but Kunipia F (Kunipia F) manufactured by Kunimine Co., Ltd., which was Na-MMT (sodium-montmorillonite), was used.

Example 27

A coating solution was prepared in the same manner as in Example 1, but bentonite WH (Southern clay) was used as clay.

Experimental Example 5

In Examples 1 and 26 and 27 above, the dissolution (dispersion) time for water at a given temperature (80 ° C.) of the solid content was measured.

As a result of the experiment, the time required for dispersion was shown in the order of Example 1> Example 27> Example 26 according to the type of clay, but Example 1 was dispersed most rapidly, but showed similar values in physical properties after coating.

Example 28

The coating solution prepared by the method of Example 1 was applied to a 20μ biaxially stretched polypropylene (BOPP) film using a coating apparatus, and then dried for 10 to 60 seconds in a hot air of 80 to 140 ° C, and then the coating film thickness was 2 μ. It was made.

Examples 29-35

To prepare a coating film in the same manner as in Example 28, the coating solution was prepared in Examples 14 to 20, respectively.

Experimental Example 6

Oxygen permeability and water vapor permeability of the coating film prepared according to Examples 28 and 29 to 35 were measured at 23 ° C. and 20% RH, respectively, and are shown in FIGS. 5 and 6.

As a result of the experiment, the oxygen permeability and the water vapor permeability of each coating film were improved as the amount of clay added increased. However, as the amount of clay added increases, it is disadvantageous in terms of economic efficiency. do.

Examples 36-42

A coating film was prepared in the same manner as in Example 28, but after drying, the coating film thickness was 0.5 μ, 1.5 μ, 3 μ, 4.5 μ, 5.5 μ, 8 μ, and 10 μ, respectively.

Experimental Example 7

Oxygen permeability and water vapor permeability of the coating film thicknesses of the coating films prepared according to Examples 28 and 36 to 42 were measured at 23 ° C. and 20% RH, respectively, and are shown in FIGS. 7 and 8.

As a result of the experiment, it was found that as the coating film thickness of the coating film was increased, the barrier property was improved, but when the thickness exceeded 10μ, the barrier property was no longer improved.

This improvement in barrier properties can be understood as a unique property expressed by completely exfoliating the nanoplatelet clay platelet lattice with polyvinyl alcohol.

Examples 43-45

A coating film was prepared in the same manner as in Example 28, but 20 μl of polyethylene (PE) film, polyester (PET) film, and nylon (nylon) film were used as coating base films.

Oxygen permeability and water vapor permeability of the coating film prepared in Examples 43 to 45 showed similar barrier properties as the coating film of Example 28, but the most economical in case of Example 28 where the coating base film is a BOPP film can do.

Experimental Example 8

Oxygen permeability according to the relative humidity of the coating film of Example 28 and the coating film prepared using the same method as Example 28, but using a general pure polyvinyl alcohol as a coating liquid (no clay), measured at a temperature of 23 ℃ 9 Shown in

As a result of the experiment, when the general pure polyvinyl alcohol was coated, it was found that the deterioration in barrier property due to humidity occurred more rapidly than the film coated with the coating liquid of the present invention.

Experimental Example 9

Table 3 compares the optical properties of the coating film of Example 28 and the general BOPP 20μ without the coating.

Change of Optical Properties after Coating division Transparency (Haze) Gloss Remarks Normal BOPP 20 μ 1.0-2.0 100-110 ASTMD1003 Example 28 1.0-2.0 110 to 120 ASTM2457

As can be seen in Table 3, the coating film of the present invention was shown that its optical properties were not significantly affected before and after coating.

Experimental Example 10

Oxygen permeability and water vapor permeability of the coating film and various packaging films of Example 28 were measured and shown in Table 4.

Comparison of barrier properties of various films Packing material Thickness (μ) Oxygen Permeability Water vapor transmission rate Packing material Thickness (μ) Oxygen Permeability Water vapor transmission rate OP 20 1500 6.3 EVA 30 8333 33.3 KOP 20 12 5 PVC 25 160 32 CP 30 3333 10 PVDC 25 1.0 1.0 PET 12 120 46 PVA 14 0.5 150 KPET 12 6 7 K-cellophane 25 10 20 ONY 15 30 180 PETG 25.4 400 64 KONY 15 5 10 VM-PET 12 One One MXD-6 15 9 42 VM-CPP 25 20 One CNY 30 40 300 Example 28 22 0.5-1.5 5.5-7.5 PE 30 1200 18 ionomer 30 5000 18

Oxygen permeability: cc / ㎡ / day (20 ℃, dry), Water vapor permeability: g / ㎡ / day (40 ℃, 90% RH)

As a result of the experiment, in the case of OP20 (abbreviation of BOPP 20μ) without coating of the present invention, the oxygen permeability showed 1500cc or more, which showed a great difference from the coating film of the present invention. I knew it was.

The coating solution and the coating film of the present invention exhibits excellent oxygen / water vapor barrier properties, and since the clay, which is an environmentally friendly material that does not generate harmful substances when incinerated, is dispersed, it is possible to eliminate the dioxin problem of the chlorine-based coating material. In addition, the barrier properties due to humidity, which is a fatal disadvantage of polyvinyl alcohol, have been improved.

In addition, since the present invention is excellent in optical properties such as transparency and gloss even after coating, it is possible to provide a coating film having high barrier properties while maintaining the optical properties inherent in the base film.

Therefore, the coating film according to the present invention can be used in various packaging materials that require oxygen / water vapor barrier properties, and can maintain excellent barrier properties even under relatively high humidity storage conditions.

Claims (10)

Solid content consisting of 70 to 99.9% by weight of polyvinyl alcohol having a degree of saponification of 50 to 99 mol% and a polymerization degree of 100 to 5000 and 0.1 to 30% by weight of clay having a diameter of 10 ^-2 to 10 ⁴ nanometers (nm) A high barrier coating liquid, comprising 100 parts by weight to 1900 parts by weight of solvent, based on 100 parts by weight. According to claim 1, wherein the clay is kaolinite, illite (illite, clay-mica), smectite (smectite), characterized in that at least one selected from the group consisting of chlorite (high), higher order Single coating solution. The method of claim 1, wherein the solvent is water, ethyl alcohol, ortho-chlorophenol (OCP), ethylene glycol (EG), dimethyl- sulfoxide (DMSO), phenol ( phenol) is at least one member selected from the group consisting of, high barrier coating liquid. 100 parts by weight of solid, consisting of 70 to 99.9% by weight of polyvinyl alcohol having a degree of saponification of 50 to 99 mol% and a polymerization degree of 100 to 5000 and 0.1 to 30% by weight of clay having a diameter of 10 ^-2 to 10 ⁴ nanometers A high barrier coating film, wherein the coating liquid comprising 100 to 1900 parts by weight of solvent is coated with a thickness of 0.5 to 10 µm on one or both surfaces of the base film. The higher order according to claim 4, wherein the clay is at least one selected from the group consisting of kaolinite, illite, clay-mica, smectite, and chlorite. Single coated film. The method of claim 4, wherein the solvent is water, ethyl alcohol, ortho-chlorophenol (OCP), ethylene glycol (EG), dimethyl- sulfoxide (DMSO), phenol ( Phenol) characterized in that at least one member selected from the group consisting of, high barrier coating film. The method of claim 4, wherein the base film is a biaxially oriented polypropylene (BOPP) film, nylon (nylon) film, polyethylene (poly-ethylene (PE) film), polyester (poly-ethylene terephtalate (PET) film, polypropylene (poly) -propylene; PP) A high barrier coating film, characterized in that one kind selected from the group consisting of films. The high barrier coating film of claim 4, wherein an adhesive primer is applied between the coating solution and the base film. 9. The high barrier coating film of claim 8, wherein the primer is a polyurethane adhesive. 10. The oxygen permeability according to any one of claims 4 to 9, wherein the oxygen permeability is 0.01 to 150 cc / m 2 / day (varies with relative humidity) and the water vapor permeability is 4 to 150 cc / m 2 / day (changes with relative humidity). Characterized in that, a high barrier coating film.