LABELED MOLDED CONTAINER HAVING LIGHT CONTRAST AT THREE-DIMENSIONAL END PORTION

Abstract

Disclosed is a labeled molded container having a container main body and a label, wherein a label surface is provided with a flat portion, a concave-convex pattern, and an edge portion between the convex portion or concave portion and the flat portion, and wherein when observing the labeled molded container from a surface-side thereof by illuminating light from a backside of the container, the edge portion is seen brighter than the flat portion and the concave-convex pattern.

Claims

1. A labeled molded container having a container main body and a label, wherein a label surface is provided with a flat portion, a concave-convex pattern, and an edge portion between the convex portion or concave portion and the flat portion, and wherein when observing the labeled molded container from a surface-side thereof by illuminating light from a backside of the container, the edge portion is seen brighter than the flat portion and the concave-convex pattern.

2. The labeled molded container according to claim 1, wherein a void decrease ratio expressed by the following equation (1) is 15% to 99%,
(1N.sub.12/N.sub.11)100 equation (1) where N.sub.11 is the number of interface voids in a thickness direction on a convex portion apex surface or concave portion bottom surface, and N.sub.12 is the number of interface voids in a thickness direction at the edge portion.

3. The labeled molded container according to claim 1, wherein the label consists of a biaxially stretched layer or a biaxially stretched layer and an unstretched layer.

4. The labeled molded container according to claim 2, wherein the label consists of a biaxially stretched layer or a biaxially stretched layer and an unstretched layer.

Description

EXAMPLES

[0247] Hereinafter, the disclosure will be more specifically described with manufacturing examples, sheet molding examples, examples, comparative examples and test examples.

[0248] The materials, using amounts, ratios, operations and the like to be described below can be appropriately changed without departing from the spirit of the disclosure. Therefore, the scope of the disclosure is not limited to specific examples to be described below.

[0249] [Measuring Methods]

[0250] (Density)

[0251] An in-mold label was cut to 100 mm in length100 mm in width and the thickness (total thickness) of each label was measured with a constant-pressure thickness gauge (model name: PG-01J, manufactured by Teclock Co., Ltd.) according to JIS K7130:1999. The mass of the in-mold label was obtained by measuring the ten samples at once with an electronic balance and determining the density by the above equation (3).

[0252] (Opacity)

[0253] An in-mold label was cut to about 75 mm150 mm, and the opacity was determined by the above procedure using a color difference meter (SM color computer manufactured by Suga Test Instruments Co., Ltd.).

[0254] (Nominal Tensile Strain at Break)

[0255] The nominal tensile strain at break was measured by a tensile tester (Shimadzu Autograph AGS-5 kNJ, manufactured by Shimadzu Corporation). The load cell and chuck for 1,000 N or 5,000 N were appropriately selected for the measurement.

[0256] (Gurley Bending Resistance)

[0257] Gurley bending resistance was measured by the above procedure for MD direction and TD direction at 23 C., 50% RH with a Gurley stiffness tester (GAS-100 manufactured by Daiei Scientific Seiki Seisakusho Co., Ltd.). Normally, 5 g weights were mounted in a hole No. 1 for the measurement.

[0258] (Thermal Conductivity)

[0259] An in-mold label was cut to about 50 mm50 mm and the thermal conductivity of the label was measured by a thermal conductivity measuring instrument (Eye Phase Mobile 1u manufactured by Eye Phase Co., Ltd.).

Manufacturing Examples

[0260] [Manufacturing of Biaxially Stretched Film of Three-Layered Structure]

Manufacturing Example 1

[0261] The materials shown in Table 1 were used, and the raw materials for the base layer (A) were melted and kneaded with the ratios shown in Table 2 by an extruder of which temperature was set to 180 C. Likewise, the raw materials for the surface layer (B) were melted and kneaded by a separate extruder of which temperature was set to 180 C. Also, the raw materials for the backside layer (C) were melted and kneaded by a separate extruder of which temperature was set to 180 C.

[0262] Then, the raw materials of the respective layers were respectively supplied to a T die of which temperature was set to 190 C., and the lamination was made in order of the surface layer (B)/the base layer (A)/the backside layer (C) in the die.

[0263] Then, the three-layered raw material was extruded into a sheet form from the T die, which was cooled to about 60 C. with cooling rolls to obtain an unstretched sheet.

[0264] The unstretched sheet was then stretched in the vertical direction by four times by using the circumferential velocity difference of a group of rolls at the sheet temperature 110 C. The sheet was then cooled to about 60 C. by the cooling rolls, so that a vertically uniaxially stretched sheet was obtained.

[0265] Then, the stretched sheet was stretched in the transverse direction by 9 times with a tentor at the sheet temperature 128 C. The sheet was then annealed to 130 C. in a heat setting zone, was cooled to about 60 C. by the cooling rolls, and was wound with an ear portion being slit, so that a biaxially stretched ethylene-based film of a three-layered structure was obtained.

[0266] The thickness of the ethylene-based film of Manufacturing Example 1 was 130 m, and the density was 0.62 g/cm.sup.3.

Manufacturing Example 2

[0267] Manufacturing Example 2 was the same as Manufacturing Example 1, except that the raw materials shown in Table 2 were used instead of the materials of Manufacturing Example 1, the setting temperature of the extruder for melting and kneading was changed to 200 C., the setting temperature of the T die was changed to 200 C., the stretching conditions were changed as shown in Table 2 and the temperature of the heat setting zone was changed to 165 C. As a result, a biaxially stretched polypropylene-based film of a three-layered structure was obtained.

[0268] The thickness of the polypropylene-based film of Manufacturing Example 2 was 107 m, and the density was 0.77 g/cm.sup.3.

Manufacturing Example 3

[0269] The materials shown in Table 1 were used, and the raw materials for the base layer (A) were melted and kneaded with the ratios shown in Table 2 by an extruder of which temperature was set to 200 C., supplied to a monolayer T die, and extruded into a film shape from the T die, which was cooled to about 60 C. with cooling rolls to obtain an unstretched sheet.

[0270] The unstretched sheet was then stretched in the vertical direction by four times by using the circumferential velocity difference of a group of rolls at the sheet temperature 100 C. The sheet was then cooled to about 60 C. by the cooling rolls, so that a vertically uniaxially stretched sheet was obtained.

[0271] Then, the raw materials for the surface layer (B) were melted and kneaded by a separate extruder of which temperature was set to 200 C. Also, the raw materials for the backside layer (C) were melted and kneaded by a separate extruder of which temperature was set to 200 C.

[0272] Then, the raw materials for the surface layer (B) were extruded into a film shape from the monolayer T die and laminated on one surface of the vertically uniaxially stretched sheet. Subsequently, the raw materials for the backside layer (C) were extruded into a film shape from the monolayer T die and laminated on one surface of the vertically uniaxially stretched sheet.

[0273] Then, the stretched sheet was stretched in the transverse direction by 9 times with the tentor at the sheet temperature 120 C. The sheet was then subjected to heating and cooling processing at 165 C. in the heat setting zone, was cooled to about 60 C. by the cooling rolls, and was wound with an ear portion being slit, so that a biaxially stretched polypropylene-based film of a three-layered structure was obtained.

[0274] The thickness of the polypropylene-based film of Manufacturing Example 3 was 83 m, and the density was 0.81 g/cm.sup.3.

[0275] Table 1 shows the materials used, Table 2 shows the manufacturing conditions of the films in the manufacturing examples 1 to 3, and Table 3 shows the physical properties of the films in the manufacturing examples 1 to 3.

TABLE-US-00001 TABLE 1 Melting peak Volume MFR temperature average Product (JIS K (JIS K particle Type Abbreviation Materials name Manufacturer 7210: 1999) 7121: 1987) size Thermoplastic PE-1 High-density NOVATEC HD Japan Polyethylene 7 g/10 min. 134 C. resin polyethylene HF560 Corporation PE-2 High-density NOVATEC HD Japan Polyethylene 0.2 g/10 min. 133 C. polyethylene HB420R Corporation PP-1 Propylene/ethylene/ NOVATEC PP Japan Polypropylene 7 g/10 min. 138 C. butene random FW4B Corporation copolymer Inorganic CA-1 Heavy calcium SOFTON #1200 Bihoku Funka 1.8 m fine powder carbonate Kogyo, Co., Ltd., TI-1 Rutile titanium TIPAQUE CR-60 Ishihara Sangyo 0.2 m dioxide Kaisha, Ltd. (: indicates there is no data)

TABLE-US-00002 TABLE 2 Stretching conditions Machine- Blending ratio of raw materials used direction Transverse Backside stretching stretching Base layer (A) Surface layer (B) layer (C) Temper- Temper- Stretched PP1 PE1 CA1 TI1 PP1 PE1 CA1 TI1 PP1 PE1 ature ratio ature ratio film (wt %) (wt %) (wt %) (wt %) (wt %) (wt %) (wt %) (wt %) (wt %) (wt %) ( C.) (times) ( C.) (times) Manufac- 0 77 22 1 0 96 2 1 0 100 100 3 120 8 turing Example 1 Manufac- 77 0 22 1 96 0 2 1 100 0 110 4 130 9 turing Example 2 Manufac- 77 0 22 1 96 0 2 1 100 0 110 4 130 9 turing Example 3

TABLE-US-00003 TABLE 3 Nominal tensile Gurley bending strain at break resistance Thermal Stretched Thickness Density Opacity MD CD MD CD conductivity film (m) (g/cm.sup.3) (%) (%) (%) (mN) (mN) (W/mK) Manufacturing 130 0.62 97 112 103 1.8 2.0 0.04 Example 1 Manufacturing 107 0.77 95 120 20 1.0 1.9 0.06 Example 2 Manufacturing 83 0.81 90 110 16 0.31 0.52 0.10 Example 3

[0276] [Manufacturing of Labeled Hollow Molded Container]

Example 1

[0277] A 0.4 L mold for in-mold forming where a cavity in which a label could be inserted was provided and the label insertion portions of the cavity were engraved with depths 1 mm and 3 mm, a width 5 mm and an angle of 90 was prepared.

[0278] The mold was mounted to an in-mold blow forming machine, and the label of Manufacturing Example 1 was inserted and fixed into the cavity.

[0279] Then, the thermoplastic material (PE-2 in Table 1), which was a material of a body part of a hollow molded container, was melted at 200 C. and was extruded into a mold of which cooling temperature was set 20 C., as the parison. The mold was then clamped, the compressed air of 30 N/cm.sup.2 was supplied into the parison, and the parison was expanded for 20 seconds into a container shape in contact with the mold and was fused to the label. The molded product was then cooled inside the mold and removed from the mold to obtain a labeled hollow molded container of Example 1. From the engraved portion having the depth 1 mm, an alphabet P stood out, and from the engraved portion having the depth 3 mm, an alphabet O stood out.

Examples 2 and 3

[0280] By performing the same processes as Example 1 except that the labels of Manufacturing Examples 2 and 3 were used instead of the label of Manufacturing Example 1 in Example 1, labeled hollow molded containers of Examples 2 and 3 were obtained.

[0281] Table 4 shows characteristic values of the labeled hollow molded container.

[0282] [Evaluation Methods]

[0283] (Number of Voids)

[0284] The cutting was made at two places so as to traverse the alphabet letter P of the labeled hollow molded container, which was then embedded with the epoxy resin and solidified. Then, a cut surface was made using microtome and was bonded to an observation sample stand. Then, the observation surface was vapor-deposited with gold-palladium and the voids of the surface were observed at a magnification of 500 times by an electron microscope (a scanning electron microscope S-2400 of Hitachi, Ltd.). The cross section was observed in a region 11 of FIG. 1 (the convex portion apex surface of the letter P) and a region 12 (between the convex portion and the flat portion of the letter P).

[0285] Then, an observation image was image-processed by an image analysis apparatus (Model Luzex IID of Nireco Co., Ltd.), and a region where the voids and the inorganic fine powders were was colored to green so as to easily count the number of the voids.

[0286] Then, 12 lines were drawn at equal intervals in the thickness direction of the cross section. The number of voids on each of ten lines except for two lines of both ends was counted, and data of 10 points was averaged, which was then set as the number of voids.

[0287] (Void Decrease Ratio)

[0288] The void decrease ratio was calculated from the number of voids N.sub.11 in the region 11 and the number of voids N.sub.12 in the region 12 by using the following equation.

(1N.sub.12/N.sub.11)100 (1)

[0289] (Light Contrast)

[0290] In a dark place, the light was illuminated from the backside of the labeled hollow molded container with a pen type lighting device, so that the light transmission of the convex portion was observed with naked eyes and determined in accordance with following standards.

[0291] A (Excellent): The outward appearance of the convex portion was strongly bright without diming.

[0292] B (Good): The outward appearance of the convex portion was slightly faintly bright.

[0293] C (Acceptable): The outward appearance of the convex portion was faintly bright.

[0294] D (Unacceptable): The outward appearance of the convex portion was not bright.

TABLE-US-00004 TABLE 4 The number of interface voids in thickness direction, Labeled the number of measurement points = 10 void hollow Apex portion of decrease molded convex portion Edge portion ratio Light container Stretched film (region 11) Average (region 12) Average (%) contrast Example 1 Manufacturing 13, 14, 15, 13, 12, 13.4 3, 4, 4, 5, 4, 5, 3.8 71.6 A Example 1 15, 13, 15, 13, 11 3, 4, 3, 3 Example 2 Manufacturing 23, 27, 24, 24, 23, 23.6 16, 15, 17, 15, 15, 14.8 37.3 B Example 2 24, 23, 22, 23, 23 15, 17, 13, 13, 12 Example 3 Manufacturing 14, 14, 15, 15, 17, 15.6 17, 13, 14, 14, 16, 14.5 7.1 D Example 3 12, 15, 18, 19, 17 11, 13, 15, 17, 15

[0295] From Table 4, when the void decrease ratio was 15% to 99%, the labeled molded container exhibiting the light contrast was obtained. In the meantime, it can be seen that the film consisting of the biaxially stretched layer is favorable as the stretched film.

DESCRIPTION OF REFERENCE NUMERALS

[0296] 1: in-mold molded container

[0297] 2: flat portion

[0298] 3: convex portion

[0299] 4: edge portion

[0300] 11: container main body

[0301] 12: in-mold label

[0302] 13: flat portion

[0303] 14: convex portion

[0304] 15: edge portion

[0305] 16: observation region of convex portion apex surface of letter P

[0306] 17: observation region between convex portion and flat portion of letter P