KR100644270B1 - Heat-shrinkable polyester film label and manufacturing method thereof - Google Patents

Abstract

The present invention is a heat-shrinkable polyester film label made of a roll of the label state by the slitting process, the central sealing process, the winding process after printing at least two widths in the fabric state, per one heat-shrinkable polyester film label Printing pattern is printed; Sealing part; The present invention relates to a heat-shrinkable polyester film label made of an uncoated portion, and formed by forming a printing layer of at least one degree or more on top and bottom uncoated portions of a label during printing.

The heat-shrinkable polyester film label of the present invention can be printed at least 1 degree or more even on the upper and lower plain portions of a label to which a printing layer is not normally applied when an ink in which a polar solvent of toluene, methyl ethyl ketone, and ethyl acetate is appropriately blended is applied. By forming a layer and manufacturing a label, problems of shrinkage finish defects such as curling of the upper and lower ends with time after printing can be solved.

Heat-shrinkable polyester film, change with time, shrinkage, poor shrinkage finish

Description

Heat-shrinkable polyester film label and its manufacturing method {HEAT-SHRINKABLE POLYESTER FILM LABEL AND MANUFACTURING METHOD THEREOF}

1 illustrates the top curl of a heat-shrinkable polyester film,

2 illustrates a printing pattern of a heat-shrinkable polyester film,

3 depicts a print pattern per one heat shrinkable polyester film label,

4 illustrates the shape of a heat shrinkable polyester film label.

<Short description of the symbols in the drawings>

1: curling upper part 2: printing part

3: solid part 4: sealing part

10: printing pattern per one heat shrinkable polyester film label

The present invention relates to a heat-shrinkable polyester film label and a method for manufacturing the same, and more particularly, to a label in which a printing layer is not normally applied when ink is applied in which a polar solvent of toluene, methyl ethyl ketone, and ethyl acetate is appropriately blended. A heat-shrinkable polyester film label in which at least one degree of printing layer is formed on the upper and lower uncoated parts and the label is manufactured, thereby eliminating shrinkage and finishing properties such as curling of the upper and lower parts due to time after printing, and a manufacturing method thereof. It is about.

In general, the heat shrinkable film is widely used for direct packaging of a plurality of containers for labeling, cap-seal, battery packaging, and the like of plastic bottles and glass bottles by using shrinkage properties by heating.

Conventionally, heat shrinkable films use polyvinyl chloride-based, polystyrene-based, polypropylene-based, or polyethylene-based films. However, polyvinyl chloride-based films generate chlorine gas and dioxins during incineration, and thus have very poor environmental friendliness.

In addition, the polystyrene-based film has good finish appearance after shrinkage, but because of poor solvent resistance, not only a special composition ink should be used for printing, but also a natural shrinkage rate is large, which makes it difficult to store.

Polypropylene film is poor in shrinkage at low temperature, wrinkles and stains are easily formed in the shrinkage portion, the film of the material is insufficient heat resistance, it is difficult to maintain the film state because it is easy to melt or rupture during the boyil or retort treatment There is this.

Therefore, in the field of heat-shrinkable films, researches on heat-shrinkable films made of polyester materials without the above problems have been actively conducted. Accordingly, the polyester film is expected to be a shrink label to replace the polyvinyl chloride film or polystyrene film, and the amount of use is gradually increasing as the use range of PET containers increases.

However, heat-shrinkable polyester film is polyethylene terephthalate (PET), which has excellent heat resistance and weather resistance and sufficient shrinkage. However, polyester ink for shrinkage film (solvent blending ratio: toluene / methyl ethyl ketone / ethyl acetate = 40%). / 40% / 20%), after a certain period of time after the printing process, the upper and lower curling occurs during the labeling process, resulting in poor shrinkage finish and lower productivity.

In general, the heat-shrinkable polyester film label is printed in two widths in the original state, and then made into a roll in a label state through a slitting process, a central sealing process, and a winding process.

Normal printing is performed by gravure printing, and a printing process of 1 to 10 degrees is performed depending on the use. In this case, the ink is an ink in which a polar solvent such as toluene, methyl ethyl ketone, ethyl acetate, etc. are blended in an appropriate ratio, and in particular, a beverage label is printed in two widths as shown in FIG . 2 . FIG. 2 illustrates a printing pattern of a heat-shrinkable polyester film, and in more detail, the printing pattern is a non-printing portion in which the sealing portion (vertical direction, 4) and the plain portion (horizontal direction, 3) are not printed at the time of printing. And a printing unit 2 printed on the inner surface of the label. The film printed in two widths is slitted at the center portion, and then the edges are folded in the center, and the sealing portion 4 is sealed with 1,3-dioxolane (1,3-dioxolane). Is made of a film label.

However, the heat shrinkable polyester film label has good shrinkage finish after initial printing (1 to 3 days) in the labeling process, but after a certain period of time, as shown in FIG. Shrinkage finish defects, such as a phenomenon, arise.

This upper and lower curling phenomenon uses a polar solvent such as toluene, methyl ethyl ketone and ethyl acetate when printing a heat-shrinkable polyester film. The boiling point of the polar solvent is 70 ° C. or higher, but the drying temperature This is because the residual solvent remains because the heat-shrinkable polyester film is dried at 60 ° C. or lower, which is dimensionally stable. The residual solvent thus generated swells the surface of the film as time passes, causing deterioration in shrinkage characteristics of the printing unit.

In addition, the upper and lower ends of the label do not normally print in order to use the sensor to detect the label between the labels when cutting the label, which causes the shrinkage rate between the printed portion and the unprinted portion that is not printed. There will be a difference. In addition, the printing surface is usually coated with a printed layer of about 1 ~ 5㎛, which causes a difference in thickness between the printed portion and the unprinted portion. Therefore, when labeling, when passing through the shrink tunnel, non-uniform shrinkage occurs due to shrinkage difference and thickness difference between the printing portion and the non-printing portion, and the non-printing portion having a relatively high shrinkage speed is rolled inward, and thus the label phase is changed according to the change over time. ㆍ Bottom curling phenomenon occurs.

In order to solve the problems of the heat-shrinkable polyester film over time, Korean Patent Publication Nos. 2005-67627, 2003-27461, 2003-30099, etc. in the polyester composition in the polyester liquid crystal polymer, polyester elastomer, It is proposed that dimer acid and / or dimer diol and / or ε-caprolactone can be used to improve the shrinkage rate and the elongation of the MD (Mechanical Direction) direction.

However, the polyester film according to the present invention can be improved to some extent the mechanical properties change according to the change over time on the fabric, the problem of changes over time such as poor shrinkage appearance after the printing process using a polar solvent is still not solved. .

Thus, the present inventors in the conventional method for producing a heat-shrinkable polyester film label, swelling due to the direct influence of the polar solvent or residual solvent after a certain time after printing using the ink consisting of a polar solvent used for printing Due to the swelling phenomenon, the shrinkage characteristics of the printing portion are reduced, and the shrinkage characteristics of the upper and lower edges during labeling are poor due to the difference in the shrinkage characteristics between the printing portion and the upper and lower plain portions that are not printed. As a result of making efforts to solve such problems, efforts have been made to at least one degree of printing layer is formed on the upper and lower plain portions of the label to which the printing layer is not normally applied, thereby improving the label printing method. The present invention was completed by confirming that the label upper and lower curling effects could be eliminated.

It is an object of the present invention to provide a heat shrinkable polyester film label in which shrinkage finish defect problems caused by polar solvents used in printing are eliminated.

It is another object of the present invention to provide a method for producing the heat-shrinkable polyester film label in which the label printing method is improved.

In order to achieve the above object, the present invention is a heat-shrinkable polyester film label made of a roll of the label state by the slitting process, the central sealing process, the winding process after printing at two or more widths in the original state, the heat shrinkage A printing part for each polyester film label; Sealing part; It provides a heat-shrinkable polyester film label consisting of a non-stick portion, wherein at the time of printing, at least 1 degree or more of the printing layer is formed on the upper and lower plain portions of the label.

The heat-shrinkable polyester film label of the present invention is characterized in that the shrinkage difference between the printed portion and the non-coated portion is 5% or less, and the thickness difference is 5 μm or less.

More specifically, at least one degree or more of a transparent printed layer is formed on the upper and lower end plain portions of the label.

In another aspect, the present invention provides a method for producing the heat-shrinkable polyester film label. More specifically

1) colored printing on the heat-shrinkable polyester film at an area of 1 degree to 10 degrees in the area where the design is printed, and forming a printing part having a thickness of 0.2 μm to 3 μm per degree,

2) transparent printing at least 1 degree or more on the non-coated parts of the upper and lower ends of the printing part, and forming a printing layer with a thickness of 0.2 μm to 3 μm per degree,

3) The printed heat-shrinkable polyester film is made of a cylindrical shape by sealing the sealing portion by slitting the central portion and then overlapping both edge portions in the width direction so as to be centered.

The printing process of steps 1 and 2 uses an ink containing 40%: 40%: 20% of a polar solvent of toluene, methyl ethyl ketone and ethyl acetate, wherein the printing speed is 50 to 200 mpm (meter per minute). Is performed.

In addition, after the printing of step 1 and step 2, the ink is dried at a temperature of 40 ~ 70 ℃, to prepare a heat-shrinkable polyester film label.

Hereinafter, the present invention will be described in detail.

The present invention is a heat-shrinkable polyester film label made of a roll of the label state by the slitting process, the central sealing process, the winding process after printing at two or more widths in the original state,

A printing unit for printing the heat-shrinkable polyester film label per printing unit (2); Sealing part 4; It provides a heat-shrinkable polyester film label consisting of a non-coating portion (3), wherein at the time of printing, at least one degree of printing layer is formed on the top and bottom of the non-coating portion (3) of the label.

That is, the heat-shrinkable polyester film label of the present invention is a printing pattern 10 per one printing portion (2); Sealing part 4; It is made of the uncoated portion 3, the sealing portion 4 which is sealed in the central sealing process and when cutting the label, the uncoated portion 3 that the sensor detects between the label and the label is an unprinted portion. Accordingly, the present invention forms a printing layer of at least one degree or more on the upper and lower plain portions 3 of the label, thereby minimizing shrinkage and thickness difference between the printing portion 2 and the plain portion 3, and thus over time after printing. The problem of poor shrinkage and finishing properties such as curling of the upper and lower ends is eliminated.

In particular, the present invention is at least 1 degree to the upper and lower end plain portions 3 of the label on which the printing layer is not applied when the polyester-based shrink film is applied with ink in which a polar solvent of toluene, methyl ethyl ketone, and ethyl acetate is appropriately blended. By forming the above-described printed layer and manufacturing the label, the occurrence frequency of the upper and lower curls of the label can be reduced to 20% or less even after 60 days, and thus the shrinkable polyester shrinkage label does not cause shrinkage finish defects. Can be provided.

In particular, in the manufacture of conventional heat-shrinkable polyester-based shrink labels, the plain portion 3 does not normally print, in order to utilize the sensor as a part for sensing between the label and the label, while the present invention is an image of the label Print at least one degree or more on the bottom uncoated portion 3 to form a transparent printed layer, so that the sensor recognizes the label smoothly between the labels when cutting the label.

At this time, in the heat-shrinkable polyester-based shrink label of the present invention, the shrinkage rate is 10 minutes in hot water maintained at 90 ℃ after taking the specimen by cutting the printed portion (2) and the plain portion (3) from the printed fabric As a result of measuring the length of the film before and after heat treatment after the second heat treatment, the shrinkage between the printing portion 2 and the non-coating portion 3 is 5% or less. As the shrinkage difference is closer to 0%, the uniform shrinkage results in better shrinkage and finish.However, if the shrinkage difference is 5% or more, the shrinkage speed of the plain portion is faster than the printing portion, and thus the shrinkage and finishing properties such as curling of the upper and lower end portions are Defects will occur.

In addition, the difference in thickness between the printing portion 2 and the non-coating portion 3 is preferably 5 μm or less. As the thickness difference approaches zero, the shrinkage difference is minimized, so that uniform shrinkage occurs and the shrinkage finish is good, while the thickness difference is good. When the thickness exceeds 5 μm, the thick printed layer inhibits the shrinkage of the label, so that the shrinkage rate of the plain portion is relatively high, resulting in poor shrinkage finish such as curling of the upper and lower plain portions.

In addition, the present invention provides a method for producing the heat-shrinkable polyester film label. More specifically

1) colored printing 1 to 10 degrees in the area in which the design is printed on the heat-shrinkable polyester film, and the printing unit 2 is formed with a thickness of 0.2 μm to 3 μm per degree,

2) transparent printing at least 1 degree or more on the upper and lower plain portions 3 of the printing unit, and forming a printing layer with a thickness of 0.2 μm to 3 μm per degree,

3) The printed heat-shrinkable polyester film is made of a cylindrical shape by sealing the sealing portion 4 by slitting the central portion and then overlapping both edge portions in the center in the width direction.

When the printing thickness is less than 0.2 μm in the printing process of steps 1 and 2, the opacity of the printing surface is lowered, and thus the product value as a label is lowered. When the thickness is more than 3 μm, it is difficult to dry, and the ink viscosity If it is low, the problem of color bleeding occurs is not preferable.

At this time, the ink used in the printing process is composed of a solvent, a coating (resin, binder), a component of the coating, additives added to improve various properties such as dispersion, drying, and curing of the paint, pigments or dyes for color realization. do. In this case, preferably, the ink is formulated with a polar solvent of 40%: 40%: 20% of toluene, methyl ethyl ketone, and ethyl acetate. In addition, the transparent ink used for transparent printing is a pigment or dye is excluded from the structural unit of the ink.

When printing on the printing unit 2 and the non-coating unit 3 using the ink, the printing speed is preferably performed at 50 to 200 mpm. At this time, if the performance is less than 50 mpm, there is a problem that the productivity is lowered, and if it exceeds 200 mpm, drying does not occur sufficiently below 70 ° C, which is not preferable because a blocking phenomenon of the print layer occurs.

In addition, after the printing of step 1 and step 2, the ink is dried at a temperature of 40 ~ 70 ℃, to prepare a heat-shrinkable polyester film label.

Hereinafter, the present invention will be described in detail by way of examples.

The following examples are merely illustrative of the present invention, but the scope of the present invention is not limited to the following examples.

<Example 1>

The green, white, and gold inks provided by Sungbo Ink Co., Ltd., in which a polar solvent of toluene, methyl ethyl ketone, and ethyl acetate were mixed in a heat shrinkable polyester film having a thickness of 50 μm with 40%: 40%: 20% Each was printed 3 degrees with a thickness of 1.0 mu m ± 0.3 mu m. At this time, looking at the printing pattern 10 per one heat-shrinkable polyester film label, the area printed per one label is 304 mm × 114 mm (orthogonal to the main shrinkage direction × main shrinkage direction). On the other hand, using a transparent ink provided by Sungbo Ink Co., Ltd., where 40%: 40%: 20% of toluene, methyl ethyl ketone, and ethyl acetate were respectively mixed on the upper and lower plain portions of the label, the thickness was 1 μm ± 0.3 μm. Printed. Printed pattern is shown in Fig.

The printed film is overlapped with both edge portions in the width direction, and the sealing portion is sealed with 1,3 dioxolane to 152 mm in width (main contraction direction) and 130 mm in length (both ends in the length direction). The heat-shrinkable polyester film label of the cylindrical shape of the part printed transparently by 8 mm space | interval was produced. The form of the prepared label is shown in Figure 4.

<Example 2>

Printed 1 degree with 2.0㎛ ± 0.3㎛ thickness using transparent ink provided by Sungbo Ink Co., Ltd., where 40%: 40%: 20% of toluene, methyl ethyl ketone, and ethyl acetate were mixed on the top and bottom of the label. Except that, in the same manner as in Example 1, to prepare a cylindrical heat-shrinkable polyester film label.

<Example 3>

Printed 1 degree with 3.0㎛ ± 0.3㎛ thickness using transparent ink provided by Sungbo Ink Co., Ltd., where 40%: 40%: 20% of toluene, methyl ethyl ketone, and ethyl acetate were mixed at the upper and lower end of the label. Except that, in the same manner as in Example 1, a cylindrical heat-shrinkable polyester film label was prepared.

<Example 4>

A cylindrical polyester film label was prepared in the same manner as in Example 1, except that the transparent ink was printed 2 degrees at a thickness of 1 μm ± 0.3 μm on the upper and lower plain portions of the label.

Example 5

A cylindrical polyester film label was prepared in the same manner as in Example 1, except that the transparent ink was printed 3 degrees at a thickness of 1 μm ± 0.3 μm on the upper and lower plain portions of the label.

Comparative Example 1

Cylindrical polyester film labels were prepared in the same manner as in Example 1, except that the upper and lower portions of the label were not printed and were made plain, as is usually printed by a printing company of shrink labels.

The heat shrinkable polyester film labels prepared in Examples 1 to 5 and Comparative Example 1 were measured as follows.

1) Thermal Shrinkage

In the printed fabric, the printed portion 2 and the plain portion 3 were cut into 5 mm in width and 100 mm in length (main contraction direction), respectively, and the specimens were collected and then heat-treated for 10 seconds in hot water maintained at 90 ° C. After measuring the length of the film before and after the heat treatment, the thermal shrinkage of the printing portion 2 and the non-coating portion 3 was calculated by the following equation (1).

(In the above, L is the length of the film before the heat treatment, l is the length of the film after the heat treatment)

2) thickness measurement

After cutting the heat-shrinkable polyester film prepared in Examples 1 to 5 and Comparative Example 1 to a width of 15 mm and a length of 200 mm in the direction to measure, using a thickness measuring instrument (Mahrgmbh, Model: Millitron) After measuring the thickness of the film 20 times at intervals of 1 cm in the longitudinal direction, the average value was taken.

3) Top and bottom curl

After the printed film was sealed with a 1,3 dioxolane so as to have a width of 152 mm and a length of 130 mm (in the length direction, both ends of which are a plain portion or a transparent printing portion), a label was prepared. The commercially available 1.5 L square heat resistant PET bottles were placed on the shoulder and torso and labeled in a hot air tunnel. Hot air tunnels were labeled with line speed 130 BPM (BOTTLE PER MINITE) under shrinkage tunnel conditions of 180 ° C / 190 ° C / 200 ° C using a labeler with the name SSI-2503 of Shinsung Engineering Co., Ltd. to observe top and bottom curls.

The upper and lower curling frequency was measured 50 times over time. After 7 days, 14 days, 30 days, 45 days, and 60 days, it was measured. Lower end curl was considered.

4) Label storage condition

The heat-shrinkable polyester film prepared in Examples 1 to 5 and Comparative Example 1 was stored in a thermo-hygrostat (TH-G manufactured by Zeotech Co., Ltd.) maintained at a temperature of 35 ° C. and a humidity of 60%, and then labeled according to time. The properties were investigated.

The measurement results are shown in Table 1 below.

From the results in Table 1, the heat-shrinkable polyester film labels of Examples 1 to 5 manufactured in the present invention are formed by forming a printing layer of at least one degree or more using a transparent ink on the upper and lower end of the label. The shrinkage ratio and the thickness difference between and the uncoated part were minimized, and the shrinkage finish defect frequency such as curling of the upper and lower ends with time after printing was reduced. In particular, in the case of Examples 4 and 5, which are printed 2 degrees on the upper and lower plain sheets, and 1 degree is printed on the upper and lower plain sheets, the coating thickness is the same as the coating thickness with the printing unit. The shrinkage finish defect frequency was significantly reduced, and the incidence of upper and lower curls was less than 20% even after 60 days in the labeling process.

On the other hand, in the case of a conventional heat-shrinkable polyester film label produced in a plain state without printing the upper and lower ends of the label (Comparative Example 1), the frequency of shrinkage finish poorness of the upper and lower curls with time after printing is increased. Increased in proportion to

As described above, the present invention

First, it provided a heat shrinkable polyester film label which does not cause shrinkage finish defects such as curling phenomenon of the upper and lower end portions due to changes in the labeling process over time.

Secondly, when the ink application in which the polar solvent of toluene, methyl ethyl ketone, and ethyl acetate is suitably blended, a printing layer is formed by forming at least one degree or more of printing layers on the upper and lower plain portions of the label to which the printing layer is not normally applied. To provide a method for producing the heat-shrinkable polyester film label improved.

Although the present invention has been described in detail only with respect to the embodiments described, it will be apparent to those skilled in the art that various modifications and variations are possible within the technical spirit of the present invention, and such modifications and variations belong to the appended claims. .

Claims (7)

In the heat-shrinkable polyester film label made of a roll of the label state by the slitting process, the central sealing process, the winding process after printing at two or more widths in the fabric state, A printing unit for printing the heat-shrinkable polyester film label; Sealing part; A heat-shrinkable polyester film label, comprising a non-woven portion, wherein at least one degree of printing layer is formed on the upper and lower non-coated portions of the label during printing. The heat-shrinkable polyester film label according to claim 1, wherein a shrinkage difference between the printed portion and the non-coated portion of the heat-shrinkable polyester film label is 5% or less. The heat-shrinkable polyester film label according to claim 1, wherein a thickness difference between the printing portion and the plain portion of the heat-shrinkable polyester film label is 5 µm or less. The heat-shrinkable polyester film label according to claim 1, wherein a transparent printing layer of at least one degree is formed on upper and lower end plain portions of the label. 1) colored printing on the heat-shrinkable polyester film at an area of 1 degree to 10 degrees in the area where the design is printed, and forming a printing part having a thickness of 0.2 μm to 3 μm per degree, 2) transparent printing at least 1 degree or more on the non-coated parts of the upper and lower ends of the printing part, and forming a printing layer with a thickness of 0.2 μm to 3 μm per degree, 3) The heat-shrinkable polyester film of claim 1, wherein the printed heat-shrinkable polyester film is made of a cylindrical shape by slitting a central portion and then sealing the sealing portion by overlapping both edge portions in the center in the width direction. Method of producing a film label. The ink of claim 5, wherein the printing of steps 1) and 2) is performed using an ink containing a polar solvent of toluene, methyl ethyl ketone, and ethyl acetate at 40%: 40%: 20%, and printing speed of 50 to 200. Method for producing the heat-shrinkable polyester film label, characterized in that performed in mpm. The method of claim 5, wherein after the printing of the step 1) and step 2), the ink is dried at a temperature of 40 ~ 70 ℃.

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