JPH02184883A - Label for in-mold label sticking and labeled plastic container - Google Patents

Abstract

PURPOSE:To prevent the generation of a blister by intrusion of air by providing many uncoated or thinly coated groove parts of small intervals arriving at the end edge of a label in at least the peripheral part of a resin adhesive layer of a label. CONSTITUTION:The label 1 consists of a label base material 2 and the resin adhesive layer 5 provided on one surface thereof; in addition, the resin adhesive layer has the many uncoated or thinly coated groove parts 7 which are provided at small intervals in at least the peripheral part of the label 1 and arrive at the end edge of the label. Such label 1 is used for in-mold label sticking, then even if the air intrudes between the label 1 and the outside surface of the container under molding, this air is escaped tough the grooves 7 provided on the surface of the resin adhesive layer 5 to the outside of the label 1 by the pressure exerted on the wall surface of the container. The generation of the blister by the intrusion of the air is prevented in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a label for attaching an in-mold label and a labeled plastic container using this label, and more specifically,
The present invention relates to a label for in-mold label application, which eliminates blistering caused by entrapment of air bubbles at the contact interface between a plastic container and the label during in-mold label application, improves the appearance characteristics of the labeled container, and increases the commercial value.

(Prior Art) Attaching a label indicating the contents to a hollow container has an important meaning in terms of packaging technology because it increases the commercial value of the packaged product and stimulates consumers' desire to purchase the product.

Applying labels to hollow containers by in-mold labeling is
It has been known for a long time, and the label to be attached to the inner surface of the cavity of the mold is held by means such as vacuum suction.
A method of blow-molding a plastic parison in this mold is generally employed (for example, Japanese Patent Laid-Open No. 61-2010
2818 Publication).

As a label for in-mold label operation, it is desirable to use a plastic film-based label because it can be printed on the back side, provides a clear image, and has excellent stain resistance. In addition, since the adhesion is performed using the heat of the wall of the plastic container that is being formed, at least the inner surface of the label must be made of a heat-bondable resin, that is, the back side of the label must be made of a heat-bondable resin film. Alternatively, it advantageously consists of a coated layer of heat-sensitive adhesive.

(Problem to be Solved by the Invention) When the label held on the mold cavity surface is bonded to the outer surface of the container being molded by the in-mold label operation, the inner surface of the label (adhering surface) and the outer surface of the container are Air is often trapped between the surface and the surface. The trapped air becomes trapped between the label and the outer surface of the container, resulting in incomplete adhesion, and when the labeled container is removed from the mold, the compressed air bubbles expand. This causes blisters. The label and container are attached from one side to the other.
Alternatively, when the process is carried out in a certain order from the center of the label to the periphery, such entrapment of air bubbles is unlikely to occur, but in the in-mold labeling operation, the label and the container wall that are being formed due to expansion etc. Since adhesion in the above order during the process cannot be expected, it is extremely difficult to prevent air from being trapped. Furthermore, if the outer surface of the container has a portion with a changing radius of curvature, a protrusion, or a four-part portion, contact between the outer surface of the container and the inner surface of the label will occur over these portions or boundary portions, making it difficult for air bubbles to form. Embracing it becomes inevitable.

However, if blisters occur on the label due to air entrapment, the blisters will be extremely noticeable due to the smoothness and gloss of the in-mold label attachment film, which will significantly impair the appearance characteristics of the labeled container and reduce its commercial value. It turns out.

Therefore, one object of the present invention is to effectively eliminate the occurrence of blisters due to air entrapment when attaching labels in molds, and as a result, it is possible to improve the appearance characteristics of labeled containers and increase their commercial value. To provide a label for attaching an in-mold label.

Another object of the present invention is to prevent the trapped air from entering the outer surface of the container, even if the outer surface of the container has a portion with a changing radius of curvature, a protrusion, or a recess, and air is trapped between the label and the outer surface of the container. To provide a plastic container with a label that can be opened to the outside and as a result, the occurrence of blisters and poor adhesion are eliminated.

Still another object of the present invention is to provide a label for in-mold label attachment and a labeled container using the same, which allows the above-mentioned blocked air to be released to the outside without impairing the beauty or display function of the label. It is in.

(Means for Solving the Problems) According to the present invention, there is provided a label that is bonded to the outer surface of a plastic container by in-mold label attachment, the label being provided on a label base material and one surface thereof. a resin adhesive layer, and the resin adhesive layer has a large number of uncoated to single-coated grooves that are provided at small intervals at least in the periphery of the label and reach the edge of the label. A label for internal labeling is provided.

According to the present invention, there is also provided a labeled plastic container in which the above-mentioned label is applied to the outer surface of the plastic container by in-mold labeling.

(Function) Since the label of the present invention is applied to the outer surface of a plastic container that is being molded by in-mold label attachment, the label is attached to the label base material and one surface thereof (the inner surface of the label). and a resin adhesive layer provided on.

In the present invention, by utilizing the fact that the resin adhesive layer is coated on the base material, at least the peripheral portion of the label resin adhesive layer is coated with a large number of uncoated or one-coated coatings at small intervals reaching the edge of the label. It is characterized by the provision of a groove. Naturally, the length of this groove is such that it reaches the edge of the label from the part where air is likely to be trapped when the label is attached to the container in the mold.

When the label of the present invention is used to attach a label in a mold, even if air is trapped between the label and the outer surface of the container that is being molded, this air is absorbed by the resin adhesive due to the pressure applied to the container wall. It escapes to the outside of the label through the grooves provided on the surface of the layer, and as a result, the occurrence of blisters is effectively prevented. It has been found that grooves with fairly small spacing are sufficient for removing air trapped between the label and the outer surface of the container. According to experiments conducted by the present inventors, the size of the blister formed by air entrainment varies depending on the shape and size of the container, but roughly speaking, the size of the blister is 20 to 1 mm in area and 30 mm in volume.
It is approximately 0.5m3 to 0.5m3, and since the molding pressure of the container is applied between the label and the container wall, as long as this groove reaches the edge of the label, air can be removed. is carried out reliably and smoothly.

Since the grooves provided in the resin adhesive layer of the label of the present invention are sufficiently spaced, in the final stage of adhesion between the label and the container wall, the grooves are filled in and sealed by the melted flow of the resin adhesive. Alternatively, even if the sealing is not complete, since most of the adhesive part is the adhesive part and the groove is a minute part, there is no appreciable effect on the adhesive strength between the label and the vessel wall or on the adhesion properties over time.

In addition, since the grooves are provided on the back side of the label base material, they do not impair the original smoothness, gloss, or aesthetics of the label, and furthermore, the occurrence of blisters is completely eliminated, making it possible to improve the quality of labeled containers. It has a great effect on improving the appearance characteristics and commercial value of the product.

(Example) The label used in the present invention includes a label base material such as a film,
Any layer structure can be adopted as long as it includes a resin adhesive and a printed image is formed. Several examples of layer configurations of this label are shown in Figures 1-A to 1-F. In Figure 1-A, this label 1 has a label base made of plastic film, metal foil, synthetic paper, or a composite thereof. Material 2,
It consists of a printed layer 3 applied to the outer surface of the base material, and a thermal adhesive resin adhesive layer 5 applied to the inner surface of the base material. 1st
The label 1 shown in FIG. 1-B is provided with a transparent overcoat layer 4 covering and protecting the printed layer 3 shown in FIG. 1-A. In the label 1 shown in FIG. 1-C, a printed layer 3 is applied as so-called back printing on the inner surface side of a film base material 2, and an adhesive resin layer 5 is provided on this printed layer 3. FIG. 1-D shows the label of FIG. 1-C in which an overcoat layer 4 is provided on the outer surface side of the film base material 2. The label l shown in Fig. 1-E has a printed layer 3 on the inner surface of a film base material 2, a thin metal layer 6 formed by vapor deposition, for example, and an adhesive resin layer 5 on top of the printed layer 3. be. This thin metal layer 6 serves to impart a metallic luster to the printed layer 6. In the label of FIG.
Of course, the laminated structure of the label used in the present invention is not limited to that exemplified above.

Examples of plastics constituting the film base material include crystalline polypropylene, crystalline propylene-ethylene copolymer, crystalline polybutene-1, crystalline poly-4-methylpentene-1, low-medium-1, or high-density polyethylene. , polyolefins such as ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), and ionically crosslinked olefin copolymer (ionomer): aromatic compounds such as polystyrene and styrene-butadiene copolymer Vinyl polymer: Polyvinyl chloride, halogenated vinyl polymer such as vinyldene chloride resin: Acrylonitrile
Nitrile polymers such as styrene copolymers, acrylonitrile-styrene-butadiene copolymers: nylon 6, nylon 6.6. Examples include polyamides such as para- or metaxylylene adipamide; polyesters such as polyethylene terephthalate and polytetramethylene terephthalate; various polycarbonates; and thermoplastic resins such as polyacetals such as polyoxymethylene. These film substrates may be unstretched (or axially or biaxially stretched), and the films may be ordinary transparent films, lightly foamed films, or It may also be a translucent to opaque film containing fillers or pigments.

The thickness of the film base material is such that it can be adhered to curved surfaces and uneven parts, and is generally in the range of 20 to 250 μm, particularly 50 to 150 μm.

The ink forming the printing layer is a vehicle of known ink used in film printing, such as polyester urethane, vinyl urethane, acrylic urethane, epoxy urethane, epoxy vinyl, epoxy acrylic, chlorinated polypropylene, etc., and colored. An ink containing a pigment is used. Printing may be performed by means such as offset printing, gravure printing, letterpress printing, electrophotographic printing, hot stamping, etc.

The resin adhesive is thermally bonded to the plastic outer wall of the container to be formed. Such hot melt adhesive resins include ethylene-vinyl acetate copolymer (EVA) having a vinyl acetate content of 5 to 40% by weight, and ethylene-ethyl acrylate copolymer having an acrylic acid content of 5 to 40% by weight. (EEA), low density polyethylene (
A mixture of 5 to 30% by weight of a tackifier such as a rosin, a terpene resin, a petroleum resin, or a styrene resin to an ethylene resin such as LDPE, EVA, or EEA is used. Chlorinated polypropylene is also used. The hot melt adhesive resin is applied on the base film at -6 to 3 to 40 μm.
The thickness is preferably 5 to 15 μm.

As the overcoat layer, a resin 5 having excellent transparency and scratch resistance, such as nitrocellulose, acrylic resin, acrylic-vinyl paint, acrylic-phenol paint, acrylic-amino paint, etc., is used. The overcoat layer is generally preferably provided with a thickness of 1 to 20 um, particularly 2 to 10 um. The thin metal layer can be provided by vapor deposition or pot stamping (transfer) of a metal such as aluminium, and its thickness is generally in the range Q,005 to 15 μm, in particular 0,01 to 9 μm.

According to the present invention, a large number of small spaces are formed in the resin adhesive layer from at least the periphery of the label, that is, the area where air is likely to be trapped between the container and the label edge, to the label edge. Provide grooves that are uncoated or coated with one coat. The portions where air is likely to be trapped are portions of the outer surface of the container where the radius of curvature changes, protrusions, recesses, or their boundary portions. A few examples will be described below.

Figures 2-A and 2-B are for explaining air entrainment during the operation of labeling in a mold into a hollow container whose body has a flat cross section. The container lO in FIG. 2-A includes a body 11, a bottom 12 connected to the lower end of the body 11, and a body 11.
It consists of a shoulder part 13 connected to the upper end and a neck part 13a above the shoulder part, and the body part 11 has a flat cross section as shown in FIG. It consists of opposing short side wall portions 15, 15 with a small radius of curvature and corner portions 16, 16, . . . with a large curvature that connect these two wall portions. For this hollow container IO, the long side wall 1
4. A label l is applied so as to cover most of 14 and straddle the corner portions 16 . The label 1 is held on the inner surface of the split molds 20a and 20b having a cavity 21 corresponding to the outer shape of the container 10 so as to correspond to the long side wall portion 14 of the container. A parison 22 for blow molding is inserted and held in the cavity 21 of the split molds 20a, 20b, and the parison 22 is expanded by fluid pressure 23 blown into the parison 22. In this case, the parison portion 25 corresponding to the short side wall portion 15 is made thicker than the parison portion 24 corresponding to the long side wall portion 14 in response to the flatness of the body portion 11. Make sure that the thickness of the part is uniform all the way around. As the fluid is blown into the parison 22, the parison expands to the state shown at 22°, and first the center of the label l comes into close contact with the parison, and this close contact gradually spreads from the center of the label l to the periphery. When the parison portion 25 expands at a speed faster than this expansion speed, an air pocket 26 is formed between the label corresponding to the corner portion 16 and the container wall, which causes the labeled container to be removed from the mold. It will blister when you take it out.

Figures 3-A and 3-B show air entrapment when operating a label in a mold for a container whose surface has irregularities such as decorative, reinforcing, or deformation-preventing beads. This is for illustrative purposes only. This container 10 has a long side wall 14.14 and a short side wall 15.15 like the containers of FIGS. 2-A and 2-B, but there is a concave (convex) wall between them. A bid 17.17... is provided, and a label l
is applied across these beads 17, 17, . When attaching the label inside the mold, the adhesion between the parison or the container wall that is being formed and the label is caused by beads 17.17...
. . , air pockets 26 are formed between the label corresponding to these boundaries 18 and the container wall.

Figures 4-A and 4-B are for explaining air entrapment during operation of an in-mold label of a container having a decorative protrusion such as a relief on the surface of the container body. This container IO also has a long side wall 14.14 and a short side 15.15, like the containers shown in FIGS. 2-A and 2-B, but the long side wall 14 has a projection such as a relief. A label l is attached to cover the protrusion 19. In this case as well, since the label and the container wall come into close contact over the boundary portion 18 of the projection 19, an air pocket 26 is formed between the label and the container wall corresponding to this boundary portion 18.

The grooves provided in the resin adhesive layer of the label are formed by not applying the resin adhesive to the part that will become the groove, or by applying the resin adhesive thinner than other parts if it is applied. The cross-sectional shape of the groove may be any shape such as a hemisphere, a semi-ellipse, a U-shape, a 7-shape, or an inverted trapezoid shape. In FIG. 5 showing an example of such grooves, in this label, grooves 7 are formed by providing uncoated parts with a certain pitch P and interval T in the adhesive layer 5 provided on the label base material 2. There is. In this case, the label base material 2 is exposed at the bottom of the full 7. In FIG. 6 showing another example of grooves, in this label 1, grooves 7 are formed by providing thin coating portions 8 with a constant pitch P and small intervals T as the adhesive layer 5. In this case, the adhesive layer 5 is also present at the bottom of the full 7.

The pitch P of the grooves 7 in the transverse direction is generally between 2 and 10
mn+, especially in the range of 3 to 5m1I+,
On the other hand, the interval (width) T of full 7 is 0.2 to 3 mm, especially 0.2 to 3 mm.
3 to 1.0 mm, and the depth D is preferably in the range of 0.001 to 0.01 mm, particularly 0.002 to 0.005 mm. If the width T and depth D of the groove 7 are smaller than the above range, the air tends to be difficult to remove smoothly, while if it is larger than the above range, the groove may cause insufficient adhesion or the appearance characteristics. There is a tendency for a decline to occur. A similar tendency exists for pitch P as well.

The grooves can be arranged in any direction such as in the axial direction of the container, in the circumferential direction of the container, in a cross-sectional direction combining these, or in an oblique direction. 7-A, 7-B, 7-C, 7-D and 7-E
The figures show some examples of the arrangement and dimensions of the label grooves 7 as applied to the labeled containers of Figures 2-A and 2-B. Note that the units of numbers in the figure are Itllll. Figure 7-A shows grooves extending in the circumferential direction of the container with a constant pitch of 5mm+.
This is an example provided in 1I11. Fig. 7-B shows an example in which a groove extending in the circumferential direction of the container is provided, and axial grooves of small length intersecting the groove are arranged at intervals. FIG. 7-C is an example in which the circumferential grooves and the 7-shaped grooves shown in FIG. 7-A are alternately arranged. Fig. 7-D is similar to Fig. 7-A, but instead of reducing the groove width T to 0.5 mm+, it is an example in which the groove pitch P is increased to 31111.

FIG. 7-E shows an example in which the groove is a cross section in the circumferential direction and the axial direction.

The adhesive can be applied and the grooves can be formed by making the adhesive resin described above into a solution or dispersion and applying this using a gravure roll or a silk screen printing method. That is, by forming the above-mentioned groove pattern on the gravure roll or screen (the groove portion is not coated or is coated thinly), the adhesive layer having the groove pattern can be easily formed. .

In addition, in the present invention, the position where blister actually occurs on the label when no groove is provided does not necessarily have to be exactly the same as the position of the groove provided on the label. This is because even though the air trapped between the two is compressed by the molding pressure applied to the vessel wall, it will flow to some extent and air will escape even through the grooves.

In FIG. 8 showing an enlarged view of the labeling part of the labeled container of the present invention, the label l is firmly connected to the container body 11 over its entire surface, but the outer surface 8 of the label 1 and the container body There is virtually no difference in level between the outer surface 27 of the outer surface 27, that is, the outer surface 27 other than the label sticking part, and the two are flush with each other.

That is, the edge portion 28 of the label l is embedded within the container body 11 to prevent curling or the like due to stress concentration on the edge portion.

The container IO may be made of the resins already mentioned for the film base material of the label, such as polyolefins, aromatic vinyl polymers,
The present invention is applicable to all of these plastic containers.
It is particularly easy to apply to polyolefin containers. The container may have a single layer structure or a multilayer laminated structure. In FIG. 9, which shows an example of a multilayer structure of a container, this container lO is
It consists of an oxygen barrier thermoplastic resin intermediate layer 29, moisture-resistant thermoplastic resin inner and outer layers 30a, 30b, and adhesive resin layers 31a, 31b inserted between both resins, if necessary.

In this case, the oxygen permeability coefficient (PO,) is 5.5 x 10-" cc・c+s in terms of the preservability and aroma retention of the contents.
/cse"5ec-co+Hg (37℃, 0%R11
) below, especially 4.5 X I O-” cc'cm/c
It is desirable to use a single thermoplastic resin or a blend of resins having a molecular weight of less than m"5 ec-co+Hg as the oxygen barrier resin.

The most preferred example of such a resin is an ethylene-vinyl alcohol copolymer, particularly one having a vinyl alcohol unit content of 40 to 85 mol%, particularly 50 to 80 mol%. Such ethylene-vinyl alcohol copolymers consist of a combination of ethylene or a large portion of ethylene with minor components of other olefins such as propylene, and vinyl esters of lower fatty acids such as vinyl formate, vinyl acetate, and vinyl propionate. It is obtained by saponifying a polymer, especially an ethylene-vinyl acetate copolymer, to a degree of saponification of 96% or more, particularly 99% or more.

Other examples of oxygen barrier resins include nylon resin,
Especially nylon 6, nylon 8, nylon 11, nylon 12, nylon 6.6, nylon 6, lO, nylon l
016, or nylon 6-6.6 copolymer.

Furthermore, high nitrile resins, vinylidene chloride resins, vinyl chloride resins, etc. can also be used for this purpose.

The oxygen barrier resin can be used in the form of a so-called blend, for example, a blend of an ethylene-vinyl alcohol copolymer and a nylon resin, or a blend of an ethylene-vinyl alcohol copolymer and a nylon resin. , other resins such as polyethylene, ethylene-vinyl acetate copolymers, or blends with ionomers may also be used for this purpose, provided their oxygen permeability coefficients are within the ranges mentioned above.

As the moisture-resistant thermoplastic resin, olefin resins such as low-1 medium- or high-density polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, etc. are preferably used.

If there is no interlayer adhesion between the oxygen barrier resin and the moisture resistant resin, an adhesive layer is interposed between both the openable layers.

As the adhesive resin (C), any resin that exhibits adhesiveness to both the oxygen barrier thermoplastic resin (A) and the moisture-resistant thermoplastic resin (B) described above can be used.

Such adhesive resin (C) generally includes free carboxylic acids, carboxylates, carboxylic esters, carboxylic acid amides, carboxylic acid anhydrides, carbonic esters, urethanes,
Thermoplastic polymers containing carbonyl groups (-C-) based on functional groups such as urea or blends of these polymers with other thermoplastic polymers are used. Although the carbonyl group concentration in these thermoplastic polymers can vary,
Generally, the carbonyl group is 10 to 1400 mmol/1
00g polymer, especially 30 to 1200 mmol/l
Suitable adhesives, preferably containing concentrations of OOg polymers, include polyolefins modified with at least one ethylenically unsaturated monomer of unsaturated carboxylic acids, acid anhydrides, esters, amides, etc. Especially maleic acid, acrylic acid, methacrylic acid, crotonic acid, fumaric acid, itaconic acid, maleic anhydride, itaconic anhydride, citraconic anhydride, ethyl acrylate, methyl methacrylate, ethyl maleate, 2-ethylhexyl acrylate,
Polypropylene modified with acrylic acid amide, methacrylic acid amide, coconut oil fatty acid amide, maleimide, etc., high-density polyethylene, low-density polyethylene, ethylene-vinyl acetate copolymer, etc., as well as ethylene-acrylate copolymer, ionomer (DuPont Surlyn A
), polyalkylene oxide/polyester block copolymers, carboxymethyl cellulose derivatives, or blends of these with polyolefins. In addition,
Among these resins, those having a low carbonyl group content can themselves be used as moisture-resistant resins.

The body of the container of the present invention can have a wide range of wall thicknesses, from so-called rigid containers to collapsible containers, for example, generally from 0.2 μm to 3.0 μm.
It can have a thickness of up to mm.

In FIG. 1O for explaining the in-mold label operation, in step A, prior to the blow molding of the plastic parison, the blow molds 32a and 32b are in an open state, and at least one of the cavity surfaces 33 is Apply label l in advance.

That is, the cavity surface 33 has a portion that supports the label l, and this portion is provided with a vacuum suction mechanism 34, and the label l is held on the cavity surface 33 by suction. In this case, the label should be positioned so that the plastic is on the inside.

The application and fixing of the label 1 to the cavity surface 33 is not limited to suction, but can also be carried out, for example, by electrostatic electricity.

Next, in step B, the dice 35. A molten plastic parison 36 is extruded from the blow molds 32a, 32.
b is closed, and pressurized gas is blown into the closed parison 36.

In step C, the parison expanding in the mold is held on the mold surface and pressed against the label 1 to bring them into close contact, and the expanded parison comes into contact with the mold surface and is cooled, forming a labeled container IO. becomes.

Blow molding can be performed using any blow molding method such as direct blow molding using horizontal rotary blow molding machines or vertical rotary blow molding machines, as well as injection blow molding, two-stage blow molding, sheet forming blow molding, stretch blow molding, etc. It can be done with

Of course, it should be understood that the molding of the labeled container of the present invention is not limited to the above-mentioned blow molding, but can also be applied to, for example, injection molding, vacuum molding, pressure molding, and the like.

(Effects of the Invention) According to the present invention, at least in the periphery of the label for in-mold label attachment, a large number of uncoated or coated grooves at small intervals are formed in the resin adhesive layer to reach the edge of the label. Even if air is trapped between the label and the container wall due to changes in curvature or irregularities on the outer surface of the container, it is possible to remove the air, eliminating blistering on the label. It has become possible to improve the appearance characteristics and commercial value of labeled containers.

[Brief description of the drawings] 1-A, 1-B, 1-C, 1-D, 1-E and 1-F
The figure is a cross-sectional view showing an example of the cross-sectional structure of a label for in-mold label attachment of the present invention. Side view and horizontal sectional view; Figures 3-A and 3-B are side views and horizontal sectional views; Figure -B is a side view and horizontal cross-sectional view for explaining air entrapment between the label and the container wall in a container with a protrusion. Figures 5 and 6 are examples of the cross-sectional shape of the label groove. Cross-sectional view shown, No. 7-A, ? -B, 7-C, 7-D and 7-E are top views showing the arrangement of the grooves on the label; FIG. 8 is an enlarged sectional view showing the label sticking part of the label sticking container; FIG. 9 is a cross-sectional view showing the cross-sectional structure of the multilayer container, and FIG. 1O is an explanatory view showing the in-mold labeling process. 1-A, 1-B, and 1-C. 1 is a label, 7 is a groove, and 1O is a container. Fig. 1-D Fig. 1-E Fig. 1-F Fig. Fig. Fig. 7-A Fig. 7-D Fig. 7-8 Fig. 7-E Fig. 1゜Process Process Fig. Process

Claims (2)

[Claims] (1) A label that is bonded to the outer surface of a plastic container by in-mold label attachment, the label consisting of a label base material and a resin adhesive layer provided on one surface of the label base material; A label for in-mold label attachment, characterized in that it has a large number of uncoated or lightly coated grooves that are provided at small intervals in at least the periphery of the label and reach the edge of the label. (2) A labeled plastic container comprising the label according to claim 1 applied to the outer surface of the plastic container by in-mold labeling.