JP6577117B2 - In-mold forming label and labeled container - Google Patents

Description

  The present invention relates to an in-mold molding label that is used as an insert material and is affixed to a peripheral wall of the container body at the same time as the molding of the container body, and a container with a label to which this label is affixed.

  As a means to achieve decoration or display of a product name or description on the surface of a synthetic resin blow-molded container, a means of sticking a label printed with a decorative pattern, product name, description, etc. is frequently used. . As one of the methods for attaching the label, a so-called in-mold molding label (hereinafter sometimes simply referred to as a label) is set in the mold in advance as an insert material, and the container body is molded. At the same time, there is an in-mold molding method in which the container body is attached to the surface of the peripheral wall.

  This in-mold molding method achieves label sticking simultaneously with the molding of the container body, does not require sticking work in a separate separate process, and there is no step between the surface of the container body and the label. It is said that there is no risk of appearance appearance and tactile deterioration due to steps, and that, for example, a strong and stable sticking of the label to the container body can be reliably obtained regardless of the thinning of the blow molded container. It has excellent points. For example, Patent Document 1 describes an invention related to a label, a blow-molded container with a label, and a manufacturing method thereof.

FIG. 12 is a cross-sectional view showing three examples of the basic layer structure of an in-mold forming label that has been generally used conventionally.
The label 111 of (a) is gravure printed on the back side of a transparent base material layer 112 made of an unstretched cast film (hereinafter abbreviated as CPP film) made of polypropylene (hereinafter abbreviated as PP) resin. The printed layer 113 is formed, a polyethylene resin is extruded and laminated by extrusion lamination, and the adhesive layer 116 is laminated.
The label 111 of (b) forms a printing layer 113 by gravure printing on the back surface of a transparent base material layer 112 made of a CPP film, and an adhesive layer 116 made of a copolymer PP resin film via a dry laminate layer 115. Laminated.
The label 111 of (c) is formed by laminating an adhesive layer 116 made of a heat seal (HS) layer on the back side of a base material layer 112 made of synthetic paper, forming a printed layer 113 by flexographic printing on the front side, and further printing layer 113 is covered with a transparent protective layer 117.

JP 2004-136486 A

Here, the region where the label as described above is pasted is conventionally limited to a two-dimensional curved surface, and it is difficult to stick to a wide range including a three-dimensional curved surface such as a spherical arc shell.
That is, a three-dimensional curved surface is a curved surface that cannot be formed by simply curving a plane-shaped label without stretching or wrinkling, and a planar label is converted into a three-dimensional curved surface by in-mold molding. When trying to forcibly stick, there is a problem that air stagnation and wrinkles are likely to occur and the appearance is damaged.
If the label can be attached to the three-dimensional curved surface, the display area can be enlarged, and the display amount can be increased, or the characters and illustrations can be enlarged, which makes it easy to see.

  Therefore, the present invention has high surface gloss and can be attached to a wide area of the peripheral wall including the three-dimensional curved surface area of the synthetic resin container body in a high quality state without air accumulation and wrinkles. It is an object to create a label for in-mold molding.

The main structure of the label of the present invention according to the means for solving the above technical problem is:
It is an in-mold molding label that is used as an insert material and is affixed to the peripheral wall of the container body simultaneously with the molding of the synthetic resin container body, and is made of a transparent synthetic resin film with a printed layer formed on the back side A base resin layer and a synthetic resin film that can be thermally welded to the peripheral wall surface of the container body, and an adhesive layer laminated on the back surface side of the base material layer via an extruded resin layer. The material layer is formed to have a flat back surface side, and the adhesive layer is formed with a regular pattern of recesses recessed to the front surface side on the back surface side, and the concave portion is formed on the front surface side with respect to the back surface side of the base material layer. Is formed between the back surface side of the base material layer and the convex and concave portions of the concave and convex pattern of the adhesive layer, and in the space, The extruded resin layer (15) is embedded, and the base material layer is The average depth of the recesses in the state where the adhesive layer is laminated is in the range of 0.02 to 0.07 mm, and the sum of the spatial volumes of the recesses per 1 cm ² of the surface area of the label is 0.0005 to 0. It is said to be in the range of .004 cm ³ .

In addition, in the said structure, the depth of a recessed part is measured by magnifying and observing the cross section of a label with a microscope. Also, the total sum of the volume of the recesses per 1 cm ² of the surface area of the label (hereinafter referred to as the total volume of the recesses) calculates the volume space per recess from the shape and depth of the recesses, and the surface area of the label 1 cm 2 Multiply by the number of recesses per ^two .

  The inventors of the present application investigated the sticking property of the in-mold label to the three-dimensional curved surface region of the peripheral wall of the synthetic resin container body, by embossing the back side of the adhesive layer that adheres to the peripheral wall of the container body. By arranging the recesses in a regular pattern and setting the depth and total volume of these recesses within an appropriate range, high-quality sticking is possible in the three-dimensional curved surface area without air accumulation and wrinkles. As a result, they have come up with the above configuration.

And according to the label for in-mold molding of the above configuration, the average depth of the recesses is in the range of 0.02 to 0.07 mm, and the total volume of the recesses per 1 cm ² of the surface area of the label is 0.0005 to 0.004 cm ^3. By providing the above range, it is possible to effectively suppress the accumulation of air and wrinkles in the three-dimensional curved surface region of the peripheral wall of the container body, and provide a labeled container with a label attached in a high quality state. It became possible.
In the above configuration and the following description, the term “back side” or “front side” is used to clarify the directionality of the label layer configuration. Here, the back side is bonded to the peripheral wall of the container body. The surface side indicates the opposite side, that is, the side exposed to the outside in a state of being attached to the container body.

If the average depth of the concave portion of the label is less than 0.02 mm, or the total volume of the concave portion per surface area of 1 cm ² is less than 0.0005 cm ³ , air is trapped in the three-dimensional curved surface area particularly during in-mold molding, and wrinkles are likely to occur. turn into.
On the other hand, if the average depth of the concave portion of the label exceeds 0.07 mm, the space formed between the base material layer and the embossed adhesive layer is not filled with molten resin during extrusion lamination, as will be described later. Air is entrained during extrusion lamination of the base material layer and the embossed adhesive layer, and a number of bubbles, so-called interlayer blisters, are generated between the layers of the label after in-mold forming, and the appearance is impaired.
Further, when the total volume of the recesses per 1 cm ^{2 of the} surface area exceeds 0.004 cm ³ , there is a problem that the adsorbability of the label by the conveying jig when inserting the label into the mold is lowered.

  In this type of label, there is a method of embossing after laminating the base material layer and the adhesive layer as a method of forming a recess on the back side of the adhesive layer, but the thickness of the adhesive layer is about 0.01 to 0.1 mm Thus, as described above, when the average depth of the recesses on the back side of the label is formed in the range of 0.02 to 0.07 mm, the embossing affects the surface side of the base material layer and the surface side of the base material layer. That is, irregularities are also formed on the surface side of the label, and the label surface is not glossy, resulting in poor quality.

In this regard, in the above-described configuration, the adhesive layer is a state in which a concave portion is formed in a regular pattern by embossing in advance on the back side of the film, with a synthetic resin film that can be thermally welded to the peripheral wall surface of the container body to be adhered. It is assumed that the substrate layer is laminated on the back side by an extrusion laminating method so that the influence of embossing does not reach the surface side of the label, and the high glossiness of the label surface can be ensured.
Another configuration of the present invention is that the extruded resin layer is embedded in the space by a sandwich extrusion lamination method.

  Here, the concave portions are formed so that the depth after lamination is about 0.02 to 0.07 mm by embossing on the back side where the thickness to be the adhesive layer is about 0.01 to 0.1 mm. When formed, irregularities are also formed on the front surface side of the adhesive layer, so that a space is formed between the back surface side of the base material layer and the concave portion formed on the front surface side of the adhesive layer. When air is entrained in the space, it is pushed by a parison during in-mold molding, the label surface swells, and there is a concern that blisters are generated between the label layers and the appearance is impaired. In the above configuration, the lamination of the base material layer and the adhesive layer is performed by extruding a molten resin such as a low density polyethylene (LDPE) resin that functions as an adhesive between the base material layer and the adhesive layer into a sheet shape. By using the laminating method, so-called sandwich extrusion laminating method, the thickness of the molten resin is about 0.01 to 0.03 mm, and the average depth of the recesses by embossing after lamination is 0 as described above. By setting the thickness to 0.07 mm or less, the molten resin can be pushed into the concave portion on the surface side of the adhesive layer, the space can be filled with the molten resin, and generation of interlayer blisters can be effectively suppressed. Become.

  Conventionally, in this type of label, the lamination of the base material layer and the adhesive layer is generally performed by a dry laminating method, but in the dry laminating method, the thickness of the adhesive is as thin as about 0.002 to 0.004 mm, Interlayer blisters are generated because the space between the recesses formed on the back surface side of the base material layer and the front surface side of the adhesive layer cannot be filled.

Another configuration of the label of the present invention is that the G value that is an index of waist strength calculated by the following formula (1) is in the range of 0.05 to 0.20 in the main configuration described above. is there.
G = E * t ³ (1)
However, E and t are as follows.
E: Tensile modulus (MPa) of the label
t: Label thickness (mm)

  The above-described configuration is a requirement for more sufficiently imparting the followability of deformation along the three-dimensional curved surface of the container of the label from the index relating to the stiffness of the label, that is, the bending rigidity of the label. With the above configuration, it is sufficient that the G value calculated from the expression (1), which is a value correlated with the bending rigidity of the label, is in the range of 0.05 to 0.20, particularly 0.20 or less. By having flexibility, the deformation along the three-dimensional curved surface of the container is sufficiently followable, and the effects and effects of the arrangement of the recesses by embossing in the main configuration described above are considered. Thus, high-quality sticking can be performed without wrinkles or the like.

Here, when the G value exceeds 0.20, in-mold molding, the followability of the planar label to the deformation along the shape of the three-dimensional curved surface region of the container becomes insufficient. Wrinkles occur on the wearing surface.
There is also a problem that when a label-attached container with a label attached is accidentally dropped, cracks are likely to occur starting from the attached peripheral edge of the label due to a drop impact.
On the other hand, if the value of waist strength is less than 0.05, the ability to automatically supply the label when setting the label on the mold surface with a machine is degraded, and wrinkles occur due to the flow of the molten resin after setting. Occurs.

  Next, the main structure of the labeled container of the present invention is that the label is affixed to the peripheral wall of the synthetic resin container body by blow molding using the in-mold molding label of the present invention described above as an insert material. .

  Another configuration of the labeled container of the present invention is that, in the above configuration, the peripheral wall of the container main body has a three-dimensional curved surface area formed in a three-dimensional curved shape.

  By using the in-mold molding label of the present invention described above, high-quality sticking is possible in a state where there is no air accumulation or wrinkles even in a three-dimensional curved region as well as a two-dimensional curved region, The label is stuck in close contact along the shape of the peripheral wall over the entire area of the sticking area, that is, the label is high in the state where there is no air accumulation, wrinkles or peeling over the whole area of the sticking area. It is possible to provide a container with a label attached to the quality.

  Still another configuration of the labeled container of the present invention is that, in the above main configuration, the average depth of the concave portion of the label after blow molding is in the range of 0.01 to 0.06 mm.

  According to the above configuration, by forming the concave portion of the label sufficiently deep after molding, a space formed between the concave portion of the adhesive layer and the wall surface of the container remains. The air between the parison wall and the label can be effectively escaped without causing the recess to be greatly crushed by heat, and the capacity to absorb the space formed by the recess is increased so that the air that has not escaped into the recess. Since it can take in and absorb, generation | occurrence | production of an air pool can fully be suppressed.

Since the present invention has the above-described configuration, the following effects can be obtained.
That is, in the in-mold molding label of the present invention, concave portions are arranged in a regular pattern by embossing on the back side of the adhesive layer bonded to the peripheral wall of the container body, and the depth and total volume of the concave portions of the label are set to a predetermined value. By setting it in an appropriate range, the label can be provided with a followable property that can be deformed along a three-dimensional curved surface, and also has a function as an air escape path by the recess and a function of absorbing air that could not be escaped. In combination with this, it is possible to effectively suppress the occurrence of air accumulation and wrinkles in the three-dimensional curved surface area, and there is no air accumulation and wrinkles in the three-dimensional curved area of the peripheral wall of the container body. It can be attached with high quality.

  In addition, by forming a concave pattern in advance in the regular pattern on the back side of the adhesive layer and laminating it on the back side of the base material layer by the extrusion laminating method, the influence of the embossing is affected by the surface of the label. As a configuration that does not extend to the side, while maintaining high gloss on the label surface, between the recess formed on the back side of the base material layer and the surface side of the adhesive film layer due to pre-embossing on the adhesive layer The space to be formed can be filled with molten resin at the time of extrusion lamination, and the generation of interlayer blisters after in-mold molding due to this space can be effectively suppressed.

It is a perspective view of one Example of the labeled container of this invention. It is a front view of the container of FIG. It is a side view of the container of FIG. (A) of the container of FIG. 1 is a plan view, (b) is a plan sectional view taken along line AA in FIG. 2, and (c) is a bottom view. It is sectional drawing which shows the laminated constitution of one Example of the label of this invention. It is a top view which shows the arrangement | positioning pattern of the recessed part seen from the back surface side of the label of FIG. It is a schematic explanatory drawing of the extrusion lamination process at the time of manufacture of the label of FIG. It is a schematic explanatory drawing which shows an example of the process for shape | molding the labeled container of this invention. It is the table | surface which put together the layer structure and property of the various labels of an Example and a comparative example. It is the table | surface which put together the evaluation results, such as a sticking state of the label in the container with various labels of the Example which uses the label in FIG. 10, and a comparative example. (A) is a label of Comparative Example 1, (b) is a label of Comparative Example 2, and (c) is a cross-sectional view showing a layer structure of a label of Comparative Example 3. It is sectional drawing which shows the example of the laminated constitution of the conventional label.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described along examples with reference to the drawings. 1 to 4 show an embodiment of a labeled container according to the present invention. FIG. 1 is a perspective view seen from the side, FIG. 2 is a front view, FIG. 3 is a side view, and FIG. (B) is the plane sectional view shown along the AA line in Drawing 2, (c) is a bottom view.
5 is a cross-sectional view showing the layer structure of an embodiment of the in-mold molding label of the present invention used in this labeled container. FIG. 6 shows the arrangement of the recesses 19 as viewed from the back side of the label in FIG. It is a top view which shows an installation pattern.
The container with a label in FIG. 1 is attached to both the front and back surfaces of the container main body 1 by an in-mold molding method using the label 11 shown in FIGS.

The container body 1 is a direct blow molded product made of PP resin, and is a casing having a cylindrical mouth tube part 2, a shoulder part 3, an elliptical cylindrical body part 4 and a bottom part 5. The total height is 155 mm and the capacity is 230 ml. The average thickness of the body part 4 is 0.50 mm.
In addition, the body 4 of the container body 1 has an oval cylindrical shape as a whole, but has a shape that is gradually reduced in diameter from the upper end to the lower end, and its peripheral wall is curved in the longitudinal direction as well as in the circumferential direction. The outer peripheral surface 4 is a three-dimensional curved surface region having a three-dimensional curved surface over substantially the entire range.
The label 11 is adhered in close contact along the three-dimensional curved surface in a wide range including the three-dimensional curved region from the upper end to the lower end on the front side of the body 4 of the container body 1. The area is attached with high quality without air accumulation, wrinkles or peeling.

  As shown in FIG. 5, the label 11 has a base layer 12 / print layer 13 / anchor coat (AC) layer 14a / extruded resin layer 15 / anchor coat (AC) layer from the surface side (from the upper side in the figure). 14 b / adhesive layer 16. Here, the base film layer 12 is made of a transparent CPP film, the layer thickness is 0.030 mm, and the adhesive layer 16 is made of a CPP film, and the layer thickness before embossing is 0.050 mm. The thickness t is 0.095 mm.

7 is a schematic explanatory view of the sandwich extrusion laminating method. In FIG. 7, (a) is an overall explanatory view of the sandwich extrusion laminating method, and (b) is an enlarged view of the vicinity of the rolls R1 and R2 in (a). FIG. 7C is a sectional view of the laminated film Fc, and the outline of the manufacturing process of the label 11 shown in FIG. 5 will be described with reference to FIG.
1) A film in which a printing layer 13 is gravure-printed on the back side of a transparent CPP film 12f to be a base layer 12, and then an AC agent is applied from the back side of the printing layer 13 and dried to laminate an AC layer 14a. Fa is supplied.
2) On the other hand, the back surface side of the CPP film 16f to be the adhesive layer 16 is embossed with an embossing roll having an embossing pattern in advance to form a recess 19, and an AC agent is applied to the surface side and dried to form an AC layer. B film Fb on which 14b is laminated is supplied.
3) Next, a molten resin Rm made of a sheet-like low density polyethylene (LDPE) resin formed by extrusion from the extruder E through a T-die T between the back side of the A film Fa and the front side of the B film Fb. A film Fa and B film Fb are laminated in an adhesive state with a molten resin Rm by a so-called sandwich extrusion laminating method, in which a laminated film Fc is produced.
4) Then, the laminated film Fc is slit and cut, and then punched into a predetermined label shape to obtain a label 11.

Here, the AC layer 14a is a layer for strengthening the adhesion between the base layer 12 made of CPP film, the extruded resin layer 15 made of LDPE resin, and the printed layer 13 and the extruded resin layer 15 made of LDPE resin. 14b is a layer for strengthening the adhesion between the extruded resin layer 15 and the adhesive layer 16 made of CPP film.
Further, the adhesive layer 16 is made of a copolymer type CPP film, and is heat-sealed directly to the peripheral wall of the container body 1 made of PP resin or polyethylene (PE) resin in in-mold molding.
In this embodiment, the printing layer 13 is formed by gravure printing, but can be formed by various printing methods such as screen printing and flexographic printing. As the anchor coating agent, for example, polyethyleneimine, polyether polyol / polyisocyanate, polyester polyol / polyisocyanate or the like diluted with water or an organic solvent can be used.

  Further, FIG. 6 shows an arrangement pattern of the recesses 19 formed in advance on the back side of the adhesive film layer 16 by embossing, and the planar shape of the recesses 19 is square, as shown in FIG. The entire surface of the label 11 is arranged in a regular pattern so as to be surrounded by the lattice-like flat portion 19f.

  Then, as shown in FIG. 5, the embossing affects the surface side of the adhesive film layer 16, and an uneven pattern is formed on this surface side so as to face the arrangement pattern of the recesses 19 on the back surface side. However, by laminating the A film Fa and the B film Fb by the sandwich extrusion laminating method described above, the projections 18b of the concavo-convex pattern formed on the back surface side of the base film layer 12 and the front surface side of the adhesive film layer 16 And the space 20 formed between the recess 18a (see FIG. 5) can be filled with the extruded resin layer 15, and the generation of interlayer blisters caused by the space 20 can be effectively suppressed. In addition, the convex part 18b of the uneven | corrugated pattern is a top part of the part which protrudes in the extrusion resin layer 15 corresponding to the recessed part 19 of the contact bonding layer 16, as shown in FIG. Moreover, the concave portion 18a of the concave / convex pattern is the surface of the adhesive layer 16 between the adjacent convex portions 18b.

Further, by laminating the A film Fa and the previously embossed B film Fb by the sandwich extrusion laminating method as described above, the influence of the embossing is exerted on the surface side of the base film layer 12, that is, the surface side of the label 11. Therefore, the surface gloss of the label 11 can be maintained at a high level. (A method for embossing the adhesive layer in advance before laminating on the base material layer is hereinafter referred to as pre-embossing. In Table 1 of FIG. 9 described later, it is described as (pre-embossing). )
The glossiness on the surface side of the label 11 of this example was 56.0%. (Measured at a measurement angle of 60 ° using Nippon Denshoku Industries VG700 in accordance with JISZ8741)

And the numerical value used as the parameter | index of the arrangement | positioning aspect of the recessed part 19 is as follows.
The average value of the depth (emboss depth) d of the recess 19 is 0.040 mm.
The total volume Vt of the recesses per 1 cm 2 surface area of the label 11 is 0.00130 cm 3 / cm 2
Moreover, the average value of the depth d of the recessed part 19 after sticking to the surrounding wall of the container main body 1 was 0.025 mm as a result of slicing a cross section in the part which the label stuck, and magnifying and observing with a microscope.

Further, the tensile modulus E was measured for the label 11 of the embodiment shown in FIG. 5 and the G value serving as an index of the waist strength of the label 11 was calculated by the following equation (1). It is 0.099 in the vertical direction of the label and 0.124 in the horizontal direction, both of which are values of 0.20 or less. From the index related to waist strength, the deformation along the three-dimensional curved surface of the container is sufficient. It has tracking ability.
G = E * t ³ (1)
However, E and t are as follows.
E: Tensile modulus (MPa) of the label
t: Label thickness (mm)
The tensile elastic modulus was obtained by punching the label into an ASTM-1822L dumbbell shape and conducting a tensile test at a tensile speed of 1 mm / min. Here, the vertical direction of the label corresponds to the axial direction of the container body when the label is attached to the container body, and the horizontal direction corresponds to a direction perpendicular thereto.

Next, FIG. 8 is a schematic explanatory diagram of the steps of the in-mold molding method for molding the labeled container of the above embodiment. A cylindrical PP resin-made parison 22 is extruded from the die 21 and the upper and lower sides thereof are sandwiched between blow molding split molds 23.
The label 11 is preliminarily adsorbed to the mold surface by the reduced pressure intake passage 24, but the portion corresponding to the three-dimensional curved surface area is not necessarily in contact with the mold surface and is partially in a floating state.
When blow air is blown in this state, the parison 22 expands (see the arrow direction in FIG. 8) and is shaped sequentially along the shape of the cavity (see the state of the two-dot chain line in FIG. 8). 4 is affixed to the peripheral wall.

  Here, the adhesive layer 16 of the label 11 is adhered to the surface of the peripheral wall of the body portion 4 of the container body 1 in a heat-welded manner in in-mold molding. At this time, in particular, as shown in FIG. 1, when the label 11 is attached to the outer peripheral surface having the three-dimensional curved surface region of the peripheral wall of the body portion 4 of the container body 1, the planar label 11 is the three-dimensional curved surface. Adhesion progresses while deforming along the surface, and air accumulation, wrinkles, and peeling are likely to occur as compared to the case of sticking to a two-dimensional curved surface. By setting the total volume Vt within a predetermined range, a function as an air escape path at the time of in-mold molding is sufficiently exhibited, and the occurrence of air accumulation at the time of attaching the label 11 is effectively prevented. In addition, the bellows effect by the concave portion is exhibited, and further, by combining the G and the G value, which is an index of waist strength, in the range of 0.05 to 0.20, it can be deformed along a three-dimensional curved surface. Followability is imparted and the generation of wrinkles is suppressed.

  Next, Table 1 in FIG. 9 shows the label (L1) of Example 1 shown in FIG. 5 and the labels (Lc1) of Comparative Examples 1, 2, 3, 4, 5, 6 prepared for comparison. , Lc2, Lc3, Lc4, Lc5, and Lc6), the layer configuration, thickness, and the depth of the recess, d, the total volume Vt, and the strength of the waist, which are indicators of the arrangement of the recesses by embossing It is the table | surface which put together G value used as a parameter | index, and the glossiness of the surface side. In the column of “Label Layer Configuration” in Table 1, the layer configuration from the front side to the back side from the left side to the right side is described. Further, the arrangement pattern of the concave portions of the labels Lc1 to Lc6 is the pattern shown in FIG. 6 similarly to the label of L1.

Table 2 in FIG. 10 uses the seven types of labels L1, Lc1, Lc2, Lc3, Lc4, Lc5, and Lc6 shown in Table 1 in FIG. 9 as insert materials, and the in-mold molding method shown in FIG. As a result of observing the presence of wrinkles, air accumulation, and interlayer blisters for seven types of labeled containers obtained by blow molding the container body 1 having the shape shown in FIG. 1 with PP resin or high density polyethylene (HDPE) resin, Furthermore, it is the table | surface which put together the result of having measured the depth of the recessed part by the embossing after shaping | molding.
The container of Example 1 (referred to as B1) uses the label 11 shown in FIG. 5, and Comparative Examples 1, 2, 3, 4, 5, 6 (Bc1, Bc2, Bc3, The containers of Bc4, Bc5, and Bc6) use the labels Lc1, Lc2, Lc3, Lc4, Lc5, and Lc6 shown in FIG.

FIG. 11A is a cross-sectional view showing the layer structure of the label of Lc1 (hereinafter, the label of L1 and the labels of Lc1 to Lc6 are simply referred to as L1 and Lc1 to Lc6). As shown in the figure, Lc1 has a layer structure of the base layer 112 / printing layer 113 / AC layer 114 / adhesive layer 116 from the surface side (from the upper side in the figure). As shown in Table 1 of FIG. 9, the base material layer 112 is made of a transparent CPP film and has a layer thickness of 0.070 mm. The adhesive layer 116 is formed by laminating an LDPE resin by an extrusion laminating method, which will be described later. The layer thickness before embossing is 0.010 mm, and the average thickness t of the entire label 111 is 0.085 mm.
Here, the concave portion 119 of the adhesive layer 116 is obtained by embossing after laminating the base material layer 112 and the adhesive layer 116 by an extrusion laminating method (embossing after laminating the base material layer and the adhesive layer in this way). The processing is hereinafter referred to as post-embossing, and is described as (post-embossing) in Table 1.) After the extrusion-laminated adhesive layer 116 is cooled and solidified with a cooling roll, the back side of the adhesive layer 116 The embossing is performed with an embossing roll having an embossing pattern, and the surface side of the label 111 is also uneven.

Then, the depth d of the concave portion of Lc1, the total volume Vt, and the range of the G value as an index of waist strength are within a predetermined range, and this Lc1 was attached to a container body made of HDPE resin by in-mold molding. In the Bc1 container (hereinafter, the B1 container and the Bc1 to Bc6 containers are simply referred to as B and Bc1 to Bc6), as shown in Table 2 of FIG. 10, the depth of the recessed portion after molding is sufficiently deep as 0.03 mm. In addition, it was in a sticking state in which no soot, air accumulation, or interlayer blistering occurred.
However, since the surface of the label is uneven due to the post-embossing, the surface glossiness is as low as 4.4% as shown in Table 1.

Next, FIG. 11B is a cross-sectional view showing the layer structure of Lc2.
This Lc2 has a layer structure of protective layer 117 / AC layer 114 / printing layer 113 / adhesive layer 116. The adhesive layer 116 is made of a CPP film and has a thickness of 0.070 mm. The protective layer 117 is formed by extruding LDPE resin. The layer structure is laminated by the laminating method, the layer thickness is 0.010 mm, the average thickness of the entire label 11 is 0.085 mm, and the layer structure is such that the layer structure of Lc1 in FIG. Thus, the adhesive layer 116 also functions as the base material layer 112. The Lc2 is obtained by post-embossing from the back side of the adhesive layer 116 after laminating the protective layer 117 and the adhesive layer 116.

  Similarly to Lc1, Lc2 has a predetermined range of the depth d of the recess, the total volume Vt, and the G value as an index of waist strength, and this Lc1 is molded in-mold into a PP resin container body. In Bc2 stuck by the above, the depth of the concave part after molding was 0.04 mm, which was sufficiently deep and without sticking, air accumulation, or generation of interlayer blisters. However, the surface of the label was uneven due to the effect of post-embossing. As shown in Table 1, the surface gloss was as low as 4.6%.

Next, FIG. 11C is a cross-sectional view showing the layer structure of Lc3.
This Lc3 has the same layer structure as Lc1 as shown in Table 1 of FIG. 9, but the adhesive layer 116 formed by laminating LDPE resin by the extrusion laminating method is used as a cooling roll having an emboss pattern. And the embossing is performed at the same time as the cooling and solidification in step B. The concave portion 119 remains in the thickness range of the adhesive layer 116 of 0.020 mm, the concave portion depth d and the total volume Vt remain small. The glossiness of the film was as high as 45.6%. However, in Bc3, the depth of the concave portion after molding was as shallow as less than 0.01 mm, and generation of wrinkles and air accumulation was observed.

  Next, the Lc4 label has a layer structure in which a heat seal (HS) layer is formed on the back side of the base layer made of synthetic paper, and then embossed with an embossing roll to form an adhesive layer. The recess remains in the thickness range of the adhesive layer, the recess depth d and the total volume Vt remain small. With Bc4, the glossiness of the surface is 28.8% and the recess depth after molding is 0.01 mm. Together with the fact that the G value is large, the generation of soot and air accumulation was observed.

  Next, Lc5 has a layer configuration in which an adhesive layer made of a CPP film whose back side is embossed in advance on a base layer made of CPP film is laminated by a dry laminate (DL) layer by a dry laminate method, It remains in the thickness range of the adhesive layer of 0.030 mm, the depth d of the recesses and the total volume Vt remain small, and with Bc5, the surface gloss is 73. However, the depth of the concave portion after molding was as shallow as less than 0.01 mm, and the G value of Lc5 was large.

Next, Lc6 has substantially the same layer structure as that of L1 shown in FIG. 5, but L1 is formed by laminating a base layer 12 and a pre-embossed adhesive layer 16 by a sandwich extrusion lamination method. On the other hand, this Lc6 is laminated by a dry laminating method. Therefore, the dry laminate layer has a thin thickness of 0.002 to 0.004 mm, and cannot sufficiently fill the space formed between the back surface side of the base material layer and the concave portion formed on the front surface side of the adhesive layer. After in-mold molding, generation of interlayer blisters due to this space is observed.
In Bc6, the glossiness of the label surface before in-mold molding is as high as 53.2%, and the recess depth d after molding is sufficiently deep as 0.025 mm, so that no generation of wrinkles or air accumulation is observed. However, the appearance was impaired due to the generation of the interlayer blister after the in-mold molding described above.

As described above, for the label L1 of the example, the labels Lc1 to Lc6 of the comparative example, the container B1 with the example, the containers Bc1 to Bc6 with the label of the comparative example, the layer structure and the properties of the label individually, and the container body Although the sticking state has been described, the following can be said when these examples and comparative examples are viewed as a whole.
First, looking at the occurrence of soot and air accumulation, as shown in Table 2 of FIG. 10, there is no soot and air accumulation in B1, Bc1, Bc2, and Bc6, and soot and air in Bc3, Bc4, and Bc5. There is a pool.
Here, the result of measuring the depth of the concave portion of the label before molding is less than 0.020 mm for Bc3, Bc4, and Bc5 where wrinkles and air accumulation occurred, and the air escape path of the concave portion during in-mold molding It is presumed that the function for preventing the occurrence of wrinkles and air stagnation is reduced due to a decrease in the function related to the above, and the function relating to the followability by the bellows effect by the recess, which enables deformation along the three-dimensional curved surface.

  That is, particularly when the label is affixed to a peripheral wall having a three-dimensional curved surface area, such as the container body 1 of the labeled container shown in FIG. 1, the recesses 19 are simply arranged in a regular pattern by embossing. It is not sufficient to provide the concave portions 19 having a predetermined range of depth d (0.02 to 0.07 mm range) in a regular pattern, and the total volume Vt of the concave portions 19 is set to a predetermined value. It turns out that it is necessary to make it into the range (0.0005-0.004 cm3 range).

  Further, when the G value is a large value exceeding 0.20, such as Lc4 and Lc5, the elasticity of the label becomes too large, and the followability to deformation along the shape of the three-dimensional curved surface region of the container is not good. It becomes sufficient and wrinkles are likely to occur on the sticking surface. Therefore, when the label is actually put into practical use, after determining the arrangement of the layer structure, the depth of the recess by embossing, the total volume, etc., as appropriate, the G value is used as an index to further determine the overall strength of the label. It is preferable to set it to an appropriate size (0.05 to 0.20).

Further, when L1, Lc5, and Lc6 adopting the pre-embossing for the adhesive layer and Lc1 and Lc2 adopting the post-embossing are compared, the glossiness of the surface of Lc1 and Lc2 is about several percent, but L1 Lc5 and Lc6 are as high as several tens of percent, and the effect of adopting the pre-embossing was confirmed.
Both L1 and Lc6 are post-embossing labels with high gloss, but L1 (B1), which uses the sandwich lamination method when laminating the base layer and the pre-embossed adhesive layer, is in-mold molding. There was no subsequent generation of interlayer blisters, and in Lc6 (Bc6) employing the dry lamination method, interlayer blisters after in-mold formation occurred, and the effect of employing the sandwich lamination method was confirmed.

As mentioned above, although the structure of this invention and its effect were demonstrated along the Example, the label of this invention and the container with a label are not limited to these Examples. For example, in the above embodiment, the container main body is formed by direct blow molding, but may be formed by biaxial stretch blow molding or thermoforming.
The layer structure of the label can be appropriately selected from various variations of the layer structure in consideration of the combination with the synthetic resin used for the container body in addition to those shown in the examples.
Further, the regular arrangement pattern of the recesses can be appropriately selected from various variations in addition to the pattern shown in FIG.

  As described above, the in-mold molding label of the present invention has high surface gloss and can be attached to a three-dimensional curved surface region of the peripheral wall of the container body without air accumulation, wrinkles, or blisters. Therefore, a container with a label to which this label is attached is expected to be widely used as a container decorated in an unprecedented manner.

DESCRIPTION OF SYMBOLS 1; Container body 2; Mouth part 3; Shoulder part 4; Trunk part 5; Bottom part 11; Label 12; Base material layer 13; Print layer 14a, 14b; Anchor coat layer 15; Concave part 18a; Concave part 18b; Convex part 19f; Flat part 20 Space 21; Die 22; Parison 23; Blow split mold 24; Depressurized intake passage 111; Label 112; Substrate layer 113; Print layer 114; Anchor coat layer 115; Laminate layer 116; adhesive layer 117; protective layer 119; recess E; extruder T; T die R1; roll R2; roll Fa; A film Fb;

Rm; Extruded molten resin 12f; Film 16f (for base layer); Film d (for adhesive layer); Depth t (for recess); Thickness (for label)

Claims (7)

An in-mold molding label that is used as an insert material and is attached to the peripheral wall of the container body simultaneously with the molding of the synthetic resin container body,
A base layer (12) made of a transparent synthetic resin film having a printed layer (13) formed on the back side;
It is a synthetic resin film that can be heat-welded to the peripheral wall surface of the container body, and has an adhesive layer (16) laminated on the back side of the base material layer (12) via an extruded resin layer (15). ,
The base material layer (12) is formed flat on the back side,
The adhesive layer (16) is formed with a regular pattern of recesses (19) that are recessed toward the front side on the back side, and the recesses (19) with respect to the back side of the base material layer (12) on the front side. ), An uneven pattern facing the arrangement pattern is formed,
A space (20) is formed between the back surface side of the base material layer (12) and the convex portions (19b) and concave portions (19a) of the concave-convex pattern of the adhesive layer (16),
The extruded resin layer (15) is embedded in the space (20),
The average depth of the recess (19) in the state where the adhesive layer (16) is laminated on the base material layer (12) is in the range of 0.02 to 0.07 mm,
The label for in-mold molding, wherein the sum of the spatial volumes of the recesses (19) per 1 cm ² of the surface area of the label is in the range of 0.0005 to 0.004 cm ³ . The in-mold molding label according to claim 1, wherein the extruded resin layer (15) is embedded in the space by a sandwich extrusion laminating method. The label for in-mold molding according to claim 1 or 2 , wherein the glossiness on the surface side of the label is 40% or more. The in-mold molding label according to any one of claims 1 to 3, wherein a G value calculated by the following formula (1) is in a range of 0.05 to 0.20.
G = E * t ³ (1)
However, E and t are as follows.
E: Tensile modulus (MPa) of the label
t: Label thickness (mm) The label (11) is affixed to a peripheral wall of the container body (1) made of synthetic resin by blow molding using the label (11) according to any one of claims 1 to 4 as an insert material. A labeled container characterized by. 6. The labeled container according to claim 5, wherein the peripheral wall of the container main body (1) has a three-dimensional curved surface area formed in a three-dimensional curved shape. The labeled container according to claim 5 or 6, wherein the average depth of the concave portion (19) of the label (11) after blow molding is in the range of 0.01 to 0.06 mm.

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