KR100837759B1 - Polyester antibiotic film - Google Patents

Abstract

The present invention is a polyester antimicrobial film comprising a polyester base layer and a coating layer on at least one side of the base layer, wherein the coating layer is an inorganic antimicrobial particle having an average particle diameter of 0.001 ~ 0.1 ㎛ made of a carrier on which an antimicrobial agent is loaded. It comprises 0.0001 ~ 0.1wt% based on the synthetic resin solids of the, the thickness of the coating layer relates to a polyester antimicrobial film, characterized in that, while retaining the basic properties of the conventional polyester resin, while excellent antimicrobial, transparency And it relates to a polyester antimicrobial film that can be used as an antimicrobial material, such as cosmetic packaging, stationery, toys, food packaging that requires the maintenance of freshness, such as vegetables, meat and so on.

Polyester base layer, antibacterial, transparency, active, inorganic antibacterial particle, silver

Description

Polyester antibacterial film {POLYESTER ANTIBIOTIC FILM}

The present invention relates to a polyester antimicrobial film having excellent antimicrobial properties, and more particularly, foods requiring maintaining the freshness of vegetables and meat by improving the antimicrobial properties, transparency, and activity while retaining the basic properties of conventional polyester resins. It relates to a polyester antimicrobial film that can be used as a packaging material, antimicrobial materials such as cosmetic containers, stationery, toys.

In general, a polyester film is a film formed by stretching and extruding a polyester resin made by polycondensation of dimethyl terephthalate and ethylene glycol or terephthalic acid and ethylene glycol. To prepare a polyester film, first, melt a polyester chip in a solid state. After extrusion, it is quenched to form an amorphous sheet, which is uniformly stretched in the longitudinal and transverse directions while heating the amorphous sheet. The polyester polymer chain is biaxially oriented by the stretching process to improve the mechanical properties of the film. In this state, the film is thermally contracted at a high temperature above the stretching temperature, thereby reducing its dimensional stability. Thus, the film undergoes a heat fixing step of crystallizing at a high temperature under tension to prevent this. Through such a heat fixing process, the polyester film has excellent characteristics and is widely used in various applications because it has various advantages over other general purpose polymer films.

Polyester films are used in a wide variety of applications. Among them, they are most commonly used for magnetic recording materials. Next, they are used not only for photography, electrical insulation, cable wrapping, capacitors, but also for deposition, tracing, agriculture, It is widely used in various high-end industrial applications such as packaging, adhesive tape, OHP, printer ribbon, magnetic card, FPC, and FRP mold release.

Recently, as interest in the health and hygiene environment increases due to improved living standards, the importance of hygiene is also recognized in plastic products, and consumers are demanding various plastic products having antibacterial function. In particular, since the polyester film is widely used as a food packaging material and a medical film, the development of the antimicrobial polyethylene terephthalate film is more important situation.

In connection with such a situation, Japanese Patent Laid-Open Nos. 2-147059 and 2-101003 use inorganic fine particles to provide antimicrobial properties to the film. In addition, Japanese Patent Application Laid-Open No. 6-049274 proposes a method of neutralizing an grafted layer of a polymer base formed by radiation with an alkaline solution and adsorbing metal silver ions through ion exchange to the polymer base. The resin blending method of the antimicrobial composition described in Japanese Patent Application Laid-Open Nos. 6-87711, 5-25012, and Korean Patent Laid-Open Publication Nos. 2000-0055768 and 1998-022261 has been described. There is a problem in exhibiting antimicrobial activity. In addition, Korean Patent Laid-Open Publication No. 1999-0079669 discloses an antimicrobial polyester film composed of a polyester film's center layer and an antimicrobial composition's surface layer, which reduces the transparency and antimicrobial properties of the film by the particles and the coating film of the surface layer. Cause On the other hand, Japanese Patent Application Laid-open No. Hei 10-086290 proposes a film in which the base film and the surface layer having antimicrobial is laminated, this method also has a disadvantage that the process efficiency is not good because it has to go through the lamination process.

The present invention has been made to solve the above problems, the object of the present invention is to improve the antimicrobial, transparency, and activity while retaining the basic properties of the conventional polyester resin as a food packaging material or antimicrobial material that requires the maintenance of freshness It is an object to provide a polyester antimicrobial film that can be used.

Polyester antimicrobial film according to the present invention for achieving the above object is a polyester antimicrobial film comprising a polyester base layer and a coating layer on at least one side of the base layer, the coating layer is an average consisting of a carrier carrying an antimicrobial agent Inorganic antimicrobial particles having a particle diameter of 0.001 ~ 0.1㎛ containing 0.0001 ~ 0.1wt% based on the synthetic resin solids of the coating layer, characterized in that the thickness of the coating layer is 0.01 ~ 1.0㎛.

The resin of the polyester base layer is characterized in that at least one selected from polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and two or more copolymers thereof.

In addition, the antimicrobial agent of the inorganic antimicrobial particles is characterized in that silver, copper, or zinc, and the carrier supporting the antimicrobial agent of the inorganic antimicrobial particles is silica, titanium oxide, zeolite, zirconium phosphate, montmorillonite, hydroxyapatite ( hydroxy apatite), phosphate complex, tripolyphosphate, magnesium aluminum silicate, calcium silicate, or soluble glass, and the synthetic resin of the coating layer is polypropylene resin, polyethylene resin, polyamide resin, polyester resin, polycarbonate resin, It is characterized in that the resin is selected from the group consisting of polyvinyl chloride (PVC) resin, polyvinylidene chloride (PVDC) resin, polystyrene resin, polyurethane resin, and acrylic polymer resin.

In addition, the polyester antimicrobial film according to the present invention after the coating layer is longitudinally stretched in the manufacturing process of the series of the polyester base layer, after being coated on at least one side of the base layer in the step before the transverse stretching or transverse stretching, It is characterized in that the coating on at least one side of the base layer.

Inorganic antimicrobial particles used in the composition forming the coating layer of the polyester antimicrobial film according to the present invention is an antimicrobial agent silver, copper, zinc and the like silica, titanium oxide, zeolite, zirconium phosphate, montmorillonite, hydroxy apatite ), A polyphosphate, a polypolyphosphate, a tripolyphosphate, magnesium aluminum silicate, calcium silicate, or a soluble glass, and the synthetic resin for blending the antimicrobial agent is a polypropylene resin, polyethylene resin, or polyamide resin. Examples include polyester resins, polycarbonate resins, polyvinyl chloride (PVC) resins, polyvinylidene chloride (PVDC) resins, polystylene resins, polyurethane resins, or acrylic polymers. However, considering the compatibility with the antimicrobial agent and process compatibility, polypropylene resin, poly It is the preferred, more preferably an ethylene resin, a polyester resin, a polyurethane resin, an acrylic polymer and the like is used a polyester resin, a polyurethane resin, an acryl-based polymer.

In addition, the molecular weight of the synthetic resin compounding the carrier carrying the antimicrobial agent used in the composition of the present invention as described above is preferably 1,000 to 100,000 g / mol, preferably 5,000 to 50,000 g / mol. The melting point of the synthetic resin is usually 200 to 265 ℃, preferably 220 to 260 ℃, the glass transition temperature of the synthetic resin is usually 40 to 120 ℃, preferably 50 to 90 ℃.

In the coating layer composition of the polyester antimicrobial film according to the present invention, various additives, for example, heat stabilizers, antioxidants, light stabilizers, nucleating agents, flame retardants, pigments, etc. , Dyes, curing agents and the like can be added.

In the coating layer composition of the polyester antimicrobial film according to the present invention, the dose and average particle diameter of the inorganic antimicrobial particles applied to the base film are closely related to the antimicrobial activity, process activity, and transparency of the polyester film. In other words, the antimicrobial mechanism continuously releases the antimicrobial component at a constant rate on the surface of the film, thereby inhibiting the intake of microorganisms or destroying the cell membranes directly, thereby showing the antimicrobial effect, or physically blocking the growth of microorganisms by the antimicrobial agent on the film surface. By showing the antimicrobial effect, there is a difference in the antimicrobial effect according to the application concentration of the antimicrobial agent. The antimicrobial effect is expressed only when the concentration of the antimicrobial agent is added in an amount of 50 to 100 times the minimum growth inhibition concentration of the selected antimicrobial agent. In addition, the amount and particle size of the inorganic particles applied to the base affect the process runability and transparency of the film.The amount of the inorganic particles is 0.0001wt% or less (based on the synthetic resin solids forming the coating layer), and the particle size is 0.001㎛ or less. This becomes unstable, and the transparency of the film is deteriorated when the amount of the inorganic particles is 0.1 wt% or more and the particle size is 0.1 mu m or more. Therefore, in order to secure the antimicrobial activity, transparency, and activity of the film separately, it can be changed according to the thickness and use of the film, but in order to simultaneously secure the antimicrobial activity, transparency, and activity of the film, the average particle diameter of the inorganic particles is 0.001 ~ 0.1㎛ Preferably, it is 0.05-0.08 micrometer, and the quantity of an inorganic particle is 0.0001-0.1 wt%, Preferably it is 0.001-0.08 wt%.

The polyester resin used for the base material layer of the polyester antibacterial film which concerns on this invention is not specifically limited. For example, those produced by condensation polymerization of aromatic dicarboxylic acids such as terephthalic acid and naphthalene dicarboxylic acid or esters thereof with glycols such as ethylene glycol, diethylene glycol, 1,4-butanediol and neopentyl glycol Although it is mentioned, Preferably a polyethylene terephthalate is used. The polyester may be a mixture of two or more kinds, and may contain an additive or the like.

The polyester of the polyester antimicrobial film according to the present invention is obtained by condensation polymerization of an aromatic dicarboxylic acid component and a glycol component. Specific examples of the aromatic dicarboxylic acid include terephthalic acid, dimethyl terephthalic acid, isophthalic acid and naphthalene dicarboxylic acid. And other aliphatic dicarboxylic acids, isophthalic acid, sulfoisophthalic acid, 1,2-cyclohexane dicarboxylic acid, 1,3-cyclohexane carboxylic acid, and others, Terephthalic acid or terephthalic acid is particularly preferred. The glycol component condensation-polymerized with dicarboxylic acid may be ethylene glycol, 1,2-propylene glycol, bisphenol-A, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, 2- Aliphatic and aromatic diols, such as methyl propanediol, are mentioned, Among these, ethylene glycol is preferable. In addition, trimellitic acid, trimellitic anhydride, pyromellitic acid, trimellirol propane, pentaerythritol and the like may be used as the copolymerization component.

As described above, the intrinsic viscosity (IV) of polyethylene terephthalate used in the present invention (measured at room temperature in phenol / 1,1,2,2-tetrachloroethane mixed solvent) is usually 0.1 to 3.0 dl / g, preferably 0.6-1.5 dl / g, more preferably 0.7-1.3 dl / g, molecular weight is 10,000-100,000 g / mol, preferably 30,000-50,000 g / mol. In addition, the melting point is usually 200 ~ 265 ℃, preferably 220 ~ 260 ℃, the glass transition temperature is usually 55 ~ 125 ℃, preferably 60 ~ 90 ℃.

In order to manufacture the polyethylene terephthalate film, which is a base layer of the polyester antimicrobial film according to the present invention, the polyethylene terephthalate is dried at a temperature of 150 ° C. under vacuum conditions for 3 hours to remove moisture therein. The dried raw material is melted / mixed / transferred through an extruder heated to 270 ° C to 290 ° C. Preferred conditions for the extruder used here include a small fluctuation in the amount of extrusion, good kneading, good dispersion and uniform extrusion, low temperature extrusion, no degradation of the resin properties, no mixing of bubbles, and the like. It is desirable to be capable of mass extrusion to satisfy. In the case where the extrusion amount exceeds 1 ton per hour, the temperature rise of the resin increases in the single screw extruder, and the quality of the resin decreases due to the deterioration of the resin and the deterioration of moldability. In such a case, a tandem extruder is used. Tandem extruder divides many functions such as solid conveying, melting, kneading, metering, and boosting of raw materials into two parts, and uses extruder of high speed and compactness with high melting efficiency. With a focus on reservoir temperature and metering, use larger and slower ones. By automatically controlling the resin pressure at the inlet of the two-stage extruder, it can be operated like a single extruder. The advantages of such an extruder can be summarized by mass extrusion, it is possible to keep the resin temperature low, the extrusion stability is good, the residence time in the extruder is short and the quality is excellent. The melted resin in the extruder passes through the disk filter and filters the large particles or foreign matter and is discharged through the die. The sheet-like molten resin extruded from the die is formed into a disc sheet by a casting machine. The condition of this disk greatly influences the quality of the final product. The die is placed in the top right corner of the roll in relation to the melt viscosity of the resin, and the resin is extruded. In order to suppress the thickness variation of the disk, it is important to minimize the vibration of the resin from the die to contact with the roll. Generally, in the polyester film, an electrostatic pinning method of applying an electrostatic charge to a molten resin and bringing it into close contact with a cooling roll is used. Generally, the sequential stretching method is employ | adopted for manufacture of a polyester film, and extending | stretching is performed in the order of longitudinal / lateral. In the longitudinal stretching process, the disc is heated in a roll group to stretch in the longitudinal direction between rolls with different circumferential speeds, and impart molecular orientation to improve the mechanical properties in the longitudinal direction. The preheating unit absorbs thermal expansion of the sheet, prevents slippage, and the stretching unit performs stretching by suppressing necking in order to maintain the uniformity and thickness accuracy of the widthwise physical properties. Longitudinal stretching temperature of the polyester film is 90 ~ 110 ℃, because it can adhere to the chromium plating roll in the stretching temperature range using an infrared heater or non-adhesive roll in the stretching portion. In addition, a multistage stretching method can be adopted to speed up the molding speed. In the lateral stretching process, the edges of the sheets after longitudinal stretching are gripped by clips, and the sheets are preheated evenly by hot air from the upper and lower sides, and stretched and heat treated in the width direction at a constant magnification according to the clip guide rails set in a predetermined pattern and then cooled. The heating chamber has a structure in which hot air that reaches the film is uniformly heated and maintains the independence of each chamber. The film from the transverse stretching machine is taken out and wound by trimming both edges. The role of the winding machine is very important with the widening of the film and the high speed of production. The polyethylene terephthalate film is corona treated on the surface to improve the adhesion, it is preferable that the biaxially stretched film to improve the mechanical properties.

The point of application of the coating layer of the polyester antimicrobial film according to the present invention is applied to one or both sides of the polyethylene terephthalate film in the stages after longitudinal stretching and before transverse stretching in a series of biaxially stretched polyethylene terephthalate film manufacturing processes ( In-line) or after application of longitudinal and transverse stretching to one or both sides of the polyethylene terephthalate film. At this time, the curing of the coating layer composition is hardened by hot air during the transverse stretching process of the film when the coating layer is applied after the longitudinal stretching, and after application when the coating layer is applied after the longitudinal stretching and transverse stretching. It is hardened by a hot air dryer. In order to harden a composition, it is preferable to set it as the process speed of 10-400MPM, and hardening temperature 30-250 degreeC, More preferably, 50-200MPM and hardening temperature 50-240 degreeC are suitable.

Application methods of the primer composition include a coating method using a roll such as a gravure roll or a reverse gravure roll, a coating method using a mayer bar, or an air knife. A general method such as a method can be used, and the thickness of the coated coating layer is 4 to 400 µm before drying, and 0.01 to 1.0 µm after drying. Before applying the coating layer, it is preferable to perform a corona discharge treatment so as to introduce polar groups on the surface of the film and to increase the surface tension to favor the coating property of the composition, and to improve the adhesion between the composition of the coating layer and the polyester resin.

Hereinafter, the present invention will be described in detail with reference to embodiments and drawings of the present invention. These examples are only for illustrating the present invention in more detail, it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples in accordance with the gist of the present invention. .

Example 1

Polyethylene terephthalate pellets with an intrinsic viscosity of 0.625dl / g containing 60 ppm of porous amorphous spherical silica particles having an average particle diameter of 3.7 µm were sufficiently dried at 160 degrees for 7 hours using a vacuum dryer, and then melted through an extrusion die. The non-stretched sheet was prepared by closely contacting the cooling drum with an electrostatic application method, and heated again, and stretched 3.5 times in a film traveling direction at 100 ° C. to prepare a uniaxially stretched film.

Separately, a silver inorganic silica, which is an antimicrobial property, is added to the pure water passed through the ion exchange resin, that is, inorganic antimicrobial particles (Nanopol), and then stirred well to form nazosol, and then sulfonated copolyester resin. WR901 (from Nippon kosei) was added and stirred to prepare a coating solution. Here, the composition was composed of the inorganic antibacterial particles of 0.05 wt% of the total weight of the resin, total solids 1.2000%. Here, 1.2000% of total solid content represents the sum total of the input amount of the inorganic antimicrobial particle and resin solidifying in the whole coating composition (water, inorganic antimicrobial particle, and resin).

Application of the composition was carried out using a Mayer bar coating method after the corona discharge treatment on the surface to be coated with the coating composition of the uniaxially stretched polyester film. The film was stretched 3.5 times in the direction perpendicular to the traveling direction of the film at 105 ° C. to 140 ° C. tender section, and then heat-treated at 240 ° C. for 4 seconds to obtain a 25 μm thick film. At this time, the thickness of the coating layer is 20nm.

Example 2

The inorganic antimicrobial particles of the coating layer composition of Example 1 were prepared in the same manner as in Example 1, except that 0.1 wt% of the total weight of the resin was composed of 1.2006% of total solids.

Example 3

The inorganic antimicrobial particles of the coating layer composition of Example 1 were prepared in the same manner as in Example 1, except that 0.01 wt% of the total weight of the resin consists of 1.1995% of total solids.

Comparative Example 1

Except for coating the composition in Example 1 was carried out in the same manner as in Example 1 to prepare a polyethylene terephthalate film.

Experimental Example 1

In this Experimental Example, the antimicrobial properties of Examples 1 to 3 and Comparative Example 1 were evaluated.

In the antimicrobial evaluation method, test bacteria were added dropwise to the surface of the test piece, adhered to the film, and after 6 hours storage at 35 ° C, the number of test bacteria on the test piece was measured. Test bacteria used were Escherichia coli and Staphylococcus.

Experimental Example 2

In the present experimental example, haze of Examples 1 to 3 and Comparative Example 1 was measured. A value of 10 cm x 10 cm sampled film is placed vertically in a haze measuring device (AUTOMATIC DIGITAL HAZEMETER manufactured by Nippon Densoku Co., Ltd.), and the value is obtained by transmitting light having a wavelength of 400 to 700 nm in a direction perpendicular to the vertically placed sample. Was measured.

At this time, the haze value is calculated by the following formula and displayed on the haze meter.

Haze (%) = (1- DF / TT) * 100

                DF: amount of scattered light

                TT: total transmittance of light

Experimental Example 3                     

In this Experimental Example, the activity of the above Examples 1 to 3 and Comparative Example 1 was measured.

In accordance with ASTM D-1894, a slippery (SLIPPERY) measuring device manufactured by Dongyang Tester was used to evaluate the lipophilic activity by applying 200 g of load and measuring static friction (μs) and dynamic friction coefficient (μk) of the coated surface.

TABLE 1

Test bacteria division Number of viable bacteria (infection rate) Haze (%) Activity μs μk Escherichia coli Example 1 <100 (99.9%) 0.98 0.47 0.35 Example 2 <50 (99.9%) 1.36 0.41 0.32 Example 3 <200 (99.9%) 0.97 0.53 0.45 Comparative Example 1 1,305,000 (0.4%) 0.98 0.54 0.48 Dropping antibacterial water 1,310,000 - - - Staphylococcus Example 1 <500 (99.9%) 0.98 0.47 0.35 Example 2 <300 (99.9%) 1.36 0.41 0.32 Example 3 <800 (99.9%) 0.97 0.53 0.45 Comparative Example 1 380,000 (15.8%) 0.98 0.54 0.48 Dropping antibacterial water 451,000 - - -

As can be seen in Table 1, Examples 1 to 3 according to the polyester antimicrobial film according to the present invention can be seen that the antibacterial properties are very excellent compared to the comparative example. In addition, it can be seen that the polyester antimicrobial film according to the present invention to which the inorganic antimicrobial particles are applied exhibits excellent diactivity while having almost the same transparency as the comparative example.

The above embodiments are intended to specifically illustrate the present invention, and do not limit the scope of the present invention. In addition, it can be seen that all simple modifications and variations of the present invention are included in the scope of the present invention.

As described above, the polyester antimicrobial film according to the present invention retains the basic properties of the conventional polyester resin, and has an excellent antimicrobial activity, transparency, and excellent activity, and thus, maintain freshness of vegetables and meat. It can be used as an antimicrobial material such as food packaging materials, cosmetic containers, stationery, toys, etc. required.

Claims (7)

In the polyester antibacterial film which comprises a biaxially stretched polyester base material layer and an antimicrobial coating layer in at least one surface of the said base material layer, The coating layer comprises 0.0001 to 0.1wt% of the inorganic antimicrobial particles having an average particle size of 0.001 ~ 0.1㎛ made of a carrier carrying an antimicrobial agent, based on the synthetic resin solid content of the coating layer, the thickness of the coating layer is 0.01 ~ 1.0㎛, Application of the coating layer is performed on at least one side of the substrate layer in a step before uniaxial stretching after the uniaxial stretching in a series of manufacturing processes of the polyester substrate layer. Polyester antibacterial film, characterized in that. The method of claim 1, The resin of the polyester base layer is at least one selected from polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and copolymers of two or more thereof, polyester antimicrobial film. The method according to claim 1 or 2, The antimicrobial agent of the said inorganic antimicrobial particle is silver, copper, or zinc, The polyester antibacterial film characterized by the above-mentioned. The method of claim 3, wherein The carrier supporting the antimicrobial agent of the inorganic antibacterial particle may be silica, titanium oxide, zeolite, zirconium phosphate, montmorillonite, hydroxy apatite, phosphate salt, tripolyphosphate, magnesium aluminum silicate, calcium silicate, or soluble glass. It is a polyester antibacterial film characterized by the above-mentioned. The method of claim 4, wherein The synthetic resin of the coating layer is polypropylene resin, polyethylene resin, polyamide resin, polyester resin, polycarbonate resin, polyvinyl chloride (PVC) resin, polyvinylidene chloride (PVDC) resin, polystyrene resin, polyurethane resin, and acrylic resin Polyester antibacterial film, characterized in that the resin selected from the group consisting of polymer resins. delete delete