WO2018003803A1

WO2018003803A1 - In-mold label and in-mold molding

Info

Publication number: WO2018003803A1
Application number: PCT/JP2017/023592
Authority: WO
Inventors: 卓哉五十嵐; 綱中村
Original assignee: 株式会社ユポ・コーポレーション
Priority date: 2016-06-30
Filing date: 2017-06-27
Publication date: 2018-01-04

Abstract

The present invention provides an in-mold label of which the printed layer is protected in a state of being stuck to a resin molding and the printed content is visible and which has sufficient adhesiveness, and a container fitted with a label which is provided with this in-mold label. An in-mold label 3 provided in a resin molding 2, wherein the in-mold label 3 is provided with a base layer 21 that includes a thermoplastic resin, and a printed layer 11, the printed layer 11 including a coloring material and an ethylene copolymer, the printed layer 11 being heat-fusible to the wall surface of the resin molding 2, the opacity of the base layer 21 being 40% or below.

Description

In-mold label and in-mold molded body

The present invention relates to an in-mold molded body in which an in-mold label is provided on a resin molded body, and the in-mold label.

Conventionally, in-mold molding has been used as one of the methods for applying a label to a resin molded body. In in-mold molding, when a resin molded body is molded in a mold, a label is placed in advance inside the mold, and the label is attached to the resin molded body at the same time as the molten resin is molded. A label used in in-mold molding is referred to as an in-mold label. From the viewpoint of decorativeness and design, a printed layer is formed by printing on the in-mold label. Usually, during in-mold molding, in-mold labels are often placed with the printed layer facing the mold. For this reason, the resin molded body to which the in-mold label is attached has a printed layer on the outer surface.

In in-mold molding, the resin constituting the resin molding is brought into contact with the resin film constituting the label in a molten state. At this time, the resin on the surface opposite to the printed layer, which exists on the surface in contact with the molten resin, melts. Then, after the molten resin of the label and the resin molded body are integrated, the label and the resin molded body are thermally fused by being cooled and solidified. Thus, in in-mold molding, a labeled in-mold molded body (hereinafter also simply referred to as “in-mold molded body”) in which the label and the resin molded body are integrally attached is molded. For this reason, the level | step difference of the label with respect to a resin molded object is suppressed, and the molded object which has shapes, such as a container which the label adhered reliably, can be shape | molded.

By the way, heat sealing adhesion is known as another technique for attaching a label to a resin molded body. In these heat seal bondings, various labels have been proposed that are used in such a manner that the printed layer is not exposed outward. For example, in patent document 1, the label which coated the surface which a heat-sensitive adhesive resin layer affixes on a target object is used. The label described in Patent Document 1 can be applied to products such as bottles and packages by activating the heat-sensitive adhesive resin layer applied to the substrate with heat and performing pressure bonding simultaneously with the heating of the label. It is a heat seal label that can be used. In this label, the base material is made of a transparent film, and an ink layer for reverse printing is formed on the heat-sensitive adhesive resin layer coated on the base material, leaving a bonded portion of the heat-sensitive adhesive resin layer.

Moreover, in patent document 2, the heat seal adhesive layer which has a thermoplastic resin, a tackifier, and a wax as a main component was provided in the one surface of the base material, and the ink layer was provided on this heat seal adhesive layer. Heat seal labels have been proposed. In the label described in Patent Document 2, tackiness is imparted to the ink layer by mixing the component of the tackifier with the ink layer by the wax contained in the heat seal adhesive layer.

Furthermore, Patent Document 3 discloses a film used as an in-mold label. The film described in Patent Document 3 is a laminate of a base film and a heat seal layer, and the heat seal layer in contact with the resin molded body has an image printed with an organic solvent-based inkjet print. And this film is integrally molded with a resin molding by the direction which a heat seal layer and a resin molding contact by in-mold molding.

On the other hand, Patent Document 4 includes a surface polymer layer containing a thermoplastic polymer as a food film used in a mode in which the printed layer is not exposed to the outside, and a polymer film form formed on the surface polymer layer. A printed polymer film containing a printed image of is described. The printed polymer film described in Patent Document 4 can protect a printed image from abrasion by further laminating a protective layer on the printed polymer film.

JP 2000-267568 A JP 2002-351323 A JP 2013-56459 A JP 2001-510592 A

In the techniques described in Patent Documents 1 to 4, a printing layer (ink layer) formed by printing is in contact with and covered with an adherend such as a bottle or a protective layer. By protecting the printed layer from being exposed to the outside in this way, wear resistance can be obtained. Furthermore, in the techniques described in Patent Documents 1 to 3, by adopting a resin film having a relatively high transparency, in a state where the label is attached to the adherend, a printing layer other than the printing layer constituting the label is used. It is also possible to read the print content of the print layer through other layers.

However, in the technique described in Patent Document 1, since the adhesive strength in the portion of the heat-sensitive adhesive resin layer provided with the ink layer is reduced, the adhesive strength as a whole label is reduced, and the attached label may be peeled off. was there.

On the other hand, in the technique described in Patent Document 2, although the adhesive force of the ink layer is improved by the wax that moves between layers, since the wax is contained as a main component, there is a possibility that the transparency may be lowered. As a result, the surface on the ink layer side becomes sticky, which may cause blocking. In the technique described in Patent Document 2, the ink that forms the ink layer is limited to the ink that is dried by the oxidation polymerization reaction.

In the technique described in Patent Document 3, since the heat fusion between the heat seal layer and the resin molded body is hindered in the image portion printed on the heat seal layer, the adhesive force is impaired. Further, in the technique described in Patent Document 3, since the image is formed by an organic solvent-based ink jet printer, the organic solvent may be eluted or volatilized from the film. In particular, leakage or volatilization of the organic solvent can occur when the film is exposed to high temperatures during in-mold molding. Then, in order to avoid adhesion failure caused by this organic solvent or to avoid this, it is considered that a separate organic solvent recovery device is required, and productivity is impaired.

On the other hand, Patent Document 4 relates to packaging materials for foods and the like, and only discloses a printed polymer film used for packaging foods, cooked food mixes, pet foods, and the like. And patent document 4 does not consider at all about the sticking to a resin molding, and the application to in-mold molding.

The present invention has been made in view of such background art. The purpose is to protect the printed layer in a state of being adhered to the resin molded body, and to visually confirm the printed content, and to provide an in-mold label having sufficient adhesion, and an in-mold label provided with the in-mold label. The object is to provide a molded body.

Note that the present invention is not limited to the purpose described here, and is an operational effect derived from each configuration shown in the embodiment for carrying out the invention described later, and can also exhibit an operational effect that cannot be obtained by the conventional technology. It can be positioned as another purpose.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that in-mold labels comprising a base material layer and a printed layer, a resin molding containing a coloring material and an ethylene copolymer and serving as an adherend It has been found that the above-mentioned problems can be solved by employing a printed layer that is heat-sealed to the wall surface of the body and a base material layer having a predetermined opacity, and the present invention has been completed.

That is, the present invention provides various specific modes shown below.
[1] An in-mold label provided on a resin molded body, comprising a base material layer containing a thermoplastic resin, and a printing layer, the printing layer containing a color material and an ethylene-based copolymer, and The in-mold label is characterized in that the printed layer can be heat-sealed to the wall surface of the resin molded body, and the opacity of the base material layer is 40% or less.

[2] The in-mold label according to [1], wherein the thermoplastic resin includes a polyolefin resin.
[3] Between the base material layer and the printing layer, further having an ink receiving layer containing a polyethylene resin, the opacity of the laminated structure having the base material layer and the ink receiving layer is The in-mold label according to [1] or [2], which is 40% or less.
[4] The in-mold label according to [3], wherein the polyethylene resin has a melting point of 135 ° C. or lower.
[5] The in-mold label according to [3] or [4], wherein the ink receiving layer has a thickness of 0.1 to 30 μm.

[6] The in-mold label according to any one of [1] to [5], wherein the ethylene copolymer has a melting point of 135 ° C. or lower.
[7] The in-mold label according to any one of [1] to [6], wherein the ethylene copolymer includes an ethylene / methacrylic acid copolymer and / or an ethylene / vinyl acetate copolymer.
[8] The in-mold label according to any one of [1] to [7], wherein the printed layer has a dot area ratio of 5 to 100%.

[9] An in-mold molded body comprising a resin molded body and an in-mold label provided on the resin molded body, wherein the in-mold label is an in-mold label according to [1] to [8] An in-mold molded body, wherein the printed layer is thermally fused to the wall surface of the resin molded body.
[10] The in-mold molded product according to [9], wherein the resin molded product includes a polyethylene resin.

ADVANTAGE OF THE INVENTION According to this invention, while a printing layer is protected in the state affixed on the resin molding, and the visual recognition of the printing content is possible, the in-mold label which has sufficient adhesiveness, and an in-mold molding are implement | achieved. be able to.

It is a perspective view which shows typically the in-mold molded object of embodiment. It is sectional drawing which shows typically the state which the in-mold label provided with the printing layer and the base material layer stuck on the wall surface of the resin molding. It is sectional drawing which shows typically the layer structure of the in-mold label in which the printing layer was provided in the base material layer partially or intermittently. It is sectional drawing which shows typically the layer structure of the in-mold label in which the printing layer was provided in the base material layer partially or intermittently, and the resin molding. It is sectional drawing which shows typically the layer structure of the in-mold label used for the comparative example a1, and the resin molding. It is sectional drawing which shows typically the layer structure of the in-mold label used for the comparative example a2, and the resin molding. It is sectional drawing which shows typically the layer structure of the in-mold label used for the comparative example a3, and the resin molding. It is sectional drawing which shows typically the layer structure of the in-mold label used for the comparative example a4, and the resin molding. It is sectional drawing which shows typically the state which the in-mold label provided with the printing layer, the ink receiving layer, and the base material layer adhered to the wall surface of the resin molding. It is sectional drawing which shows typically the layer structure of the in-mold label in which the printing layer was provided in the ink receiving layer partially or intermittently. It is sectional drawing which shows typically the layer structure of the in-mold label in which the printing layer was provided in the ink receiving layer partially or intermittently, and the resin molding. It is sectional drawing which shows typically the layer structure of the in-mold label used for the comparative example b1, and the resin molding. It is sectional drawing which shows typically the layer structure of the in-mold label used for the comparative example b2, and the resin molding. It is sectional drawing which shows typically the layer structure of the in-mold label used for the comparative example b3, and the resin molding. It is sectional drawing which shows typically the layer structure of the in-mold label used for the comparative example b4, and the resin molding.

Hereinafter, each embodiment of the present invention will be described with reference to the drawings. The following embodiments are examples for explaining the present invention, and the present invention is not limited only to the embodiments. In the following, unless otherwise specified, positional relationships such as up, down, left, and right are based on the positional relationships shown in the drawings. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios. In the present specification, for example, the description of a numerical range of “1 to 100” includes both the lower limit value “1” and the upper limit value “100”. This also applies to other numerical range notations.

The in-mold molded body according to the present embodiment will be described with reference to FIGS. In this embodiment, the labeled container 1 having a particularly preferable bottle-like hollow shape will be described as an example of the in-mold molded body. As shown in FIG. 1, the labeled container 1 includes a resin molded body 2 and an in-mold label 3 provided on the outer surface of the resin molded body 2. As shown in FIG. 2, the in-mold label 3 has a layer configuration of the in-mold label 3 a including the printing layer 11 and the base material layer 21. Hereinafter, the layer configuration of the in-mold label 3a is also referred to as “two-layer type”. Alternatively, as shown in FIG. 9, the in-mold label 3 further includes an ink receiving layer 31 between the printing layer 11 and the base material layer 21, so that the printing layer 11, the base material layer 21, and the ink receiving layer are provided. The layer structure of the in-mold label 3b is provided. At this time, the printing layer 11 is provided on the surface of the laminated structure 41 on the ink receiving layer 31 side. That is, the in-mold label 3b has at least the printing layer 11, the ink receiving layer 31, and the base material layer 21 in this order. Hereinafter, the layer structure of the in-mold label 3b is also referred to as “three-layer type”. In the case where the in-

mold labels

3a and 3b are not particularly distinguished from each other, there may be a case where the reference is given as “in-mold label 3”. Hereinafter, each member which comprises the container 1 with a label is demonstrated in detail.

[1. In-mold label]
<Print layer>
The print layer 11 is a layer constituting the in-mold label 3. In the in-mold label 3a, the printing layer 11 is provided on the base material layer 21. In the in-mold label 3b, the printing layer 11 is provided on the surface of the laminated structure 41 on the ink receiving layer 31 side. The printing layer 11 contacts the molten resin constituting the resin molded body 2 in a molding machine (for example, a mold) during in-mold molding. The printing layer 11 is melted by the heat of the molten resin, so that the printed layer 11 is fused with the molten resin and further cured after cooling, thereby contributing to the adhesion between the wall surface of the resin molded body 2 and the in-mold label 3. That is, the printed layer 11 can heat-bond the in-mold label 3 to the wall surface of the resin molded body 2 in this way. The print layer 11 is a layer containing a color material and an ethylene-based copolymer. In addition, the printing layer 11 usually has a color material and an ethylene copolymer as main components, and a resin film layer made of an ethylene copolymer containing a color material is preferable. Here, the main component means that the total amount of the color material and the ethylene-based copolymer in the printing layer 11 is 50% by mass or more.

In the in-mold label 3a, the printing layer 11 may be provided over the entire surface of the base material layer 21 as shown in FIG. 2, and partially or intermittently on the base material layer 21 as shown in FIG. It may be provided. Alternatively, in the in-mold label 3b, the printing layer 11 may be provided over the entire surface of the ink receiving layer 31 as shown in FIG. 9, and partially or intermittently on the ink receiving layer 31 as shown in FIG. May be provided. That is, the printed layer 11 may or may not be a uniform layer, but the adhesive property between the base material layer 21 or the ink receiving layer 31 and the resin molded body 2 can be increased via the printed layer 11. From the viewpoint of enhancing, a uniform layer is preferable. As an aspect in which the printing layer 11 is provided partially or intermittently on the base material layer 21 or the ink receiving layer 31, there is a case where the printing layer 11 is provided so as to constitute a character or a pattern. Or the case where the printing layer 11 is provided in patterns, such as a dot shape, stripe shape, a check shape, is mentioned. Or the printing layer 11 may be provided so that a position, a shape, and a magnitude | size may be randomly arrange | positioned on both sides of the gap between adjacent printing layers 11.

Examples of printing methods for forming the printing layer 11 include offset printing, letterpress printing, flexographic printing, gravure printing, screen printing, and ink jet printing. In addition, the type of ink attached to the printing layer 11 may be appropriately selected according to the printing method, and is not particularly limited. From the viewpoint of transferability and adhesion of ink to the base material layer 21 and the ink receiving layer 31, liquid electrostatic ink (typically, Hewlett-Packard electro ink) is preferably used as the toner composition. . The printing layer 11 of the present embodiment is preferably a toner printing layer formed of a liquid ink containing thermoplastic toner particles in which a coloring material is blended in a binder of a thermoplastic resin containing an ethylene copolymer. More preferably, the thermoplastic toner particles are charged. More preferably, printing is performed by transferring thermoplastic toner particles by electrophotography. Particularly preferably, it is formed using a liquid electro-ink containing the thermoplastic toner particles. When the printing layer 11 is formed using this type of electro ink, the printing method is preferably offset printing, more preferably digital offset printing, from the viewpoints of handling a small lot and productivity.

Hereinafter, the case where the printing layer 11 is formed by offset printing will be described. Here, an example in the case of using liquid electro-ink as a toner composition will be described, but the present invention is not limited to this, and the printing layer 11 is a layer containing a color material and an ethylene-based copolymer. It may be formed using another printing method or a toner composition.

(Toner composition)
The toner composition contains a color material and an ethylene copolymer. The toner composition preferably further contains a liquid carrier and a charge control compound. The toner composition is more preferably charged. The toner composition may further contain a dispersion stabilizer that stabilizes the electrical properties of the charge control compound. The printed layer 11 is formed by adhering (or transferring, transferring, etc.) such a color material and an ethylene copolymer dispersed on the base material layer 21 or the ink receiving layer 31. Can do. That is, the printing layer 11 is a polymer film composed of an ethylene-based copolymer, and the polymer film contains a color material.

(Liquid carrier)
The liquid carrier dissolves, disperses or emulsifies the color material and the ethylene copolymer in the toner composition. The liquid carrier is not particularly limited, but a nonpolar liquid having a low dielectric constant is preferably used. The nonpolar liquid preferably has an electrical resistivity of at least 10 ⁹ Ω · cm or more and a dielectric constant of less than 3.0. Nonpolar liquids include aliphatic hydrocarbons, aromatic hydrocarbons, light mineral oils, and the like, but are not particularly limited thereto. Among the aliphatic hydrocarbons, branched chain aliphatic hydrocarbons are preferable, and for example, Isopar (registered trademark) series isoparaffin hydrocarbons (manufactured by ExxonMobil) are preferably used. The content of the liquid carrier is not particularly limited, but is preferably 10 to 99% by mass, more preferably 30 to 90% by mass, and further preferably 50 to 80% by mass with respect to the total amount of the toner composition.

(Ethylene copolymer)
Examples of the ethylene copolymer contained in the printing layer 11 include ethylene and vinyl esters such as vinyl acetate and vinyl propionate; (meth) acrylic acid; methyl (meth) acrylate, ethyl (meth) acrylate, ( (Meth) acrylic acid esters such as meth) butyl acrylate; 3 to 10 carbon atoms such as propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene and 4-methyl-1-pentene Α-olefin; terephthalic acid; copolymers with one or more comonomers selected from alkyl terephthalates such as butyl terephthalate, but are not particularly limited thereto. In this specification, (meth) acrylic acid includes both acrylic acid and methacrylic acid. Among these, from the viewpoint of adhesion to the base material layer 2 or the ink receiving layer 31 and the resin molding 2, an ethylene / vinyl acetate copolymer and an ethylene / methacrylic acid copolymer are preferable, and an ethylene / methacrylic acid copolymer is preferable. A polymer is more preferred. The content of ethylene units in the ethylene copolymer is not particularly limited, but is preferably 40 to 95% by mass, more preferably 50 to 90% by mass, and still more preferably 60 to 85% by mass. The content of the ethylene copolymer is not particularly limited, but is preferably 5 to 80% by mass, more preferably 10 to 60% by mass, and still more preferably 15 to 40% by mass with respect to the total amount of the toner composition. is there.

Here, the print layer 11 preferably contains an ethylene copolymer having a melting point of 135 ° C. or lower. In this case, when the polymer film image is transferred using the toner composition, it is easy to form the printing layer 11 on the base material layer 21 or the ink receiving layer 31. Moreover, the adhesiveness of the printing layer 11 and the resin molding 2 can also be improved. From the above viewpoint, the upper limit of the melting point of the ethylene copolymer contained in the printing layer 11 is preferably 135 ° C, more preferably 130 ° C, still more preferably 125 ° C, particularly preferably 120 ° C, and the lower limit is The temperature is preferably 65 ° C, more preferably 75 ° C, still more preferably 85 ° C, and particularly preferably 90 ° C. The melting point of the ethylene-based copolymer contained in the printing layer 11 is preferably 65 ° C. to 135 ° C., more preferably 75 ° C. to 130 ° C., further preferably 85 ° C. to 125 ° C., particularly preferably 90 ° C. to 120 ° C. When the melting point of the ethylene copolymer constituting the print layer 11 exceeds the lower limit of the above range, stickiness can be suppressed at normal temperature and blocking can be prevented. Further, the melting point of the ethylene copolymer constituting the printing layer 11 is lower than the upper limit of the above range, so that the adhesion between the printing layer 11 and the base material layer 21 or the ink receiving layer 31 and the printing layer 11 and the resin are increased. There exists a tendency for adhesiveness with the molded object 2 to improve. In the present specification, the melting point of the resin means a value obtained from the temperature of the endothermic peak obtained by differential scanning calorimetry (DSC). Further, the melting point of the ethylene copolymer constituting the printing layer 11 is preferably 5 ° C. or more, more preferably 10 ° C. or more lower than the melting point of the thermoplastic resin constituting the resin molding 2. Thereby, there exists a tendency for the adhesiveness of the printing layer 11 and the resin molding 2 to improve.

(Coloring material)
As the color material, a known dye or pigment used for printing ink can be used. The pigment may be an organic pigment or an inorganic pigment. Examples of the dye include, but are not particularly limited to, azo dyes, anthraquinone dyes, indigo dyes, cyanine dyes, quinoline dyes, benzoquinone dyes, naphthoquinone dyes, and phthalocyanine dyes. Examples of the organic pigment include, but are not limited to, quinacridone pigments such as quindagenta, azo pigments such as toluidine red, phthalocyanine pigments such as monastral blue, monastral green, and the like. Examples of the inorganic pigment include carbon black, metal oxides such as Fe, Co, Ni, and Ti, ferrites and alloys of metals such as Zn, Cd, Ba, and Mg, but are not particularly limited thereto. Among these, a pigment is preferable, and an organic pigment and an inorganic pigment are more preferable. The content of the color material is not particularly limited, but is preferably 0.1 to 35% by mass, more preferably 1 to 30% by mass, and still more preferably 5% for the dye and the organic pigment with respect to the total amount of the toner composition. To 25% by mass. In the case of inorganic pigments, the content is preferably 0.1 to 80% by mass, more preferably 10 to 70% by mass, and still more preferably 30 to 50% by mass.

(Charge control compound)
The charge control compound is used to control the charge polarity and charge amount of the thermoplastic toner particles. As the charge control compound, an anionic, cationic, amphoteric or nonionic surfactant compound is used. One of these charge control compounds may be used alone, or two or more thereof may be used in combination. More specifically, as the charge control compound, metal soap such as barium petroleum acid, phospholipid such as lecithin, metal salt compound of organic acid, organic phosphate compound, organic sulfonic acid compound, quaternary ammonium salt compound, etc. Although it is mentioned, it is not specifically limited to these. The content of the charge control compound is not particularly limited, but is preferably 0.1% by mass to 5% by mass, more preferably 0.5% by mass to 4% by mass, and still more preferably based on the total amount of the toner composition. 1% by mass to 3% by mass.

(Dispersion stabilizer)
A dispersion stabilizer is used to help stabilize the charge control compound. Examples of the dispersant include, but are not limited to, polyvinyl pyrrolidone, polyvinyl alcohol, polyethylene glycol, and polyethylene glycol.

(Preparation of toner composition)
The toner composition can be prepared by mixing the colorant and the ethylene copolymer with heating to form thermoplastic toner particles in a liquid carrier, and further adding a charge control compound as necessary. it can. Note that wax may be mixed with the colorant when preparing the toner composition, but the printing layer 11, the base material layer 21, or the ink receiving layer 31 of the present embodiment may be made of resin without containing wax. Sufficient adhesion with the molded body 2 is obtained. For this reason, it is preferable that the toner composition and the printing layer 11 are waxless without a wax.

(Formation of printing layer)
The printing layer 11 can be formed by performing offset printing using liquid electro ink. First, a cylindrical image forming plate is charged by corona discharge, and then this image forming plate is exposed to form an electrostatic image. Next, the electrostatic image is developed by supplying a toner composition to the image plate on which the electrostatic image is formed. Further, the electrostatic toner image formed by the toner composition is transferred from the image forming plate to a cylindrical blanket. The toner composition transferred to the blanket is heated by the blanket to fuse or aggregate the thermoplastic toner particles contained in the toner composition. As the fusing or agglomeration proceeds, the thermoplastic toner particles form a polymer film, and a polymer film image containing a colorant in the polymer film is formed on the blanket. The polymer film image formed in this manner is transferred from the blanket to the base material layer 21 or the ink receiving layer 31, and further cooled and cured, whereby the printed layer 11 is formed.

(Ink density)
The ink concentration indicates the ratio of the area of the printing layer 11 to the area of the base material layer 21 or the ink receiving layer 31. When the printing layer 11 is formed on the base material layer 21 or the ink receiving layer 31 by the above-described method, the printing layer 11 is a collection of dot-like inks (network) formed on the base material layer 21 or the ink receiving layer 31. Point). For this reason, the ink density can be represented by a halftone dot area ratio indicating a ratio of an area occupied by a halftone dot portion on the base material layer 21 or the ink receiving layer 31. In the in-mold label 3, the lower limit of the halftone dot area ratio occupied by the printing layer 11 is preferably 5%, more preferably 10%, still more preferably 15%, particularly preferably 20%, and most preferably 30%. On the other hand, the upper limit is 100%, preferably 90%, more preferably 85%, still more preferably 80%, and particularly preferably 70%. In particular, in the in-mold label 3a, the dot area ratio occupied by the printing layer 11 is preferably 20 to 100%, more preferably 30 to 90%, still more preferably 40 to 85%, and particularly preferably 50 to 80%. is there. In the in-mold label 3b, the dot area ratio occupied by the printing layer 11 is preferably 5 to 100%, more preferably 10 to 90%, still more preferably 15 to 80%, and particularly preferably 20 to 70%. is there. When the ink concentration of the in-mold label 3 is within the above range, sufficient adhesion between the in-mold label 3 on which the printed layer 11 is formed and the resin molded body 2 tends to be easily exhibited. In this specification, the halftone dot area ratio is obtained by, for example, taking an image on the printed layer 11 side of the in-mould label 3 using a CCD camera, and obtaining the ratio of the area of the printed halftone dots by image processing. This means the value calculated.

(Print layer thickness)
The thickness of the printing layer 11 is appropriately changed according to the printing method and the toner composition, and is not particularly limited, but is preferably 0.5 to 10 μm, more preferably 0.8 to 5 μm, and still more preferably 1.0 to 3 μm. When the printing layer 11 is within the above range, the ink concentration is sufficiently maintained, visibility can be improved, and sufficient adhesiveness tends to be maintained.

<Base material layer>
The base material layer 21 is a layer constituting the in-mold label 3a. The base material layer 21 is a layer that supports the printing layer 11 and gives the in-mold label 3 a rigidity (stiffness) that can be handled during printing or processing. Further, the base material layer 21 functions as a printing base film for receiving the printing of the printing layer 11 and providing the printing layer 11. Furthermore, the base material layer 21 exists on the outer surface of the labeled container 1 in a state where the printed layer 11 is thermally fused to the resin molded body 2, and also functions as a protective layer for the printed layer 11.

In the case of the in-mold label 3 b further including the ink receiving layer 31, the base material layer 21 is a layer constituting the laminated structure 41 together with the ink receiving layer 31. In this case, in the in-mold label 3b, the base material layer 21 is provided on the surface opposite to the printing layer 11 with the ink receiving layer 31 interposed therebetween. The base material layer 21 is a layer that supports the printing layer 11 and the ink receiving layer 31 and gives the in-mold label 3b rigidity (stiffness) that can be handled during printing or processing. In addition, the base material layer 21 exists on the outer surface of the labeled container 1 in a state where the printing layer 11 is thermally fused to the resin molded body 2, and also functions as a protective layer for the printing layer 11 and the ink receiving layer 31.

Usually, since the thickness of the printing layer 11 is sufficiently thinner than the base material layer 21, when the printing layer 11 is melted by the heat of the molten resin in in-mold molding, the base material layer 21 is also heated by the molten resin. Is transmitted, and the base material layer 21 is also partially melted, so that the base material layer 21 can contribute to adhesion to the resin molded body 2. As shown in FIG. 3, when the printing layer 11 is not provided on the entire surface of the base material layer 21, that is, provided only on a part of the base material layer 21, The molten resin constituting the resin molded body 2 in the mold comes into contact with the portion of the base material layer 21 that is not covered with the printing layer 11. At this time, as shown in FIG. 4, the base material layer 21 melted by the heat of the molten resin is fused with the molten resin so as to fill the gaps between the printing layers 11 provided partially or intermittently. Curing after cooling contributes to the adhesion between the resin molded body 2 and the in-mold label 3a. As shown in FIG. 10, when the printing layer 11 is not provided on the entire surface of the ink receiving layer 31, that is, when it is provided only on a part of the ink receiving layer 31, the in-mold molding is performed. The molten resin constituting the resin molded body 2 in the mold comes into contact with the portion of the ink receiving layer 31 that is not covered with the printing layer 11. At this time, as shown in FIG. 11, the ink receiving layer 31 melted by the heat of the molten resin is fused with the molten resin so as to fill a gap between the partially or intermittently provided printing layers 11. It hardens after cooling and contributes to the adhesion between the resin molded body 2 and the in-mold label 3b.

A known material can be used for the base material layer 21, and the kind thereof is not particularly limited. The base material layer 21 is a layer containing a thermoplastic resin. The base material layer 21 is usually a resin film layer mainly composed of a thermoplastic resin. In particular, when the ink receiving layer is not provided, the thermoplastic resin preferably contains a polyolefin resin, and more preferably contains a polyolefin resin as a main component. Here, the main component means a component contained in the base material layer 21 by 50 mass% or more with respect to the total amount of the base material layer 21. The base material layer 21 is usually made of a thermoplastic resin film.

(Thermoplastic resin)
The thermoplastic resin contained in the base material layer 21 is not particularly limited as long as it is a material that can be formed into a film shape. Examples of the thermoplastic resin contained in the base material layer 21 include polyolefin resins, functional group-containing polyolefin resins, polystyrene resins, polyester resins, polycarbonate resins, and polyamide resins, but are not particularly limited thereto. .

Examples of the polyolefin-based resin contained in the base material layer 21 include high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE), linear low density polyethylene (L-LDPE), and ultra-low density. Polyethylene (VLDPE), ethylene / α-olefin copolymer, ethylene / vinyl acetate copolymer, ethylene / (meth) acrylic acid copolymer, ethylene / (meth) acrylic acid alkyl ester copolymer, ethylene / (meta ) Metal salts of acrylic acid copolymers, polyethylene resins such as maleic acid-modified polyethylene; homopolymers of propylene showing isotactic or syndiotactic stereoregularity, propylene / α-olefin copolymers, maleic acid Polypropylene resin such as modified polypropylene; polymethyl-1 -Pentene; ethylene / cyclic olefin copolymer; and the like, but are not particularly limited thereto. In the above ethylene / α-olefin copolymer or propylene / α-olefin copolymer, examples of the α-olefin copolymer include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, Examples thereof include α-olefins having 3 to 10 carbon atoms such as 1-octene and 4-methyl-1-pentene. In addition, these copolymers may be either random copolymers or block copolymers. In the ethylene / (meth) acrylic acid alkyl ester copolymer, the alkyl group preferably has 1 to 8 carbon atoms. Examples of the metal in the metal salt of the ethylene / (meth) acrylic acid copolymer include Zn, Al, Li, K, and Na.

Examples of the polystyrene resin contained in the base material layer 21 include atactic polystyrene, syndiotactic polystyrene, and a styrene / maleic acid copolymer. Examples of the polyester resin contained in the base material layer 21 include polyethylene terephthalate, polyethylene terephthalate isophthalate, polybutylene terephthalate, polybutylene succinate, polybutylene adipate, and polylactic acid. Examples of the polycarbonate resin contained in the base material layer 21 include aromatic polycarbonate and aliphatic polycarbonate. Examples of the polyamide resin contained in the base material layer 21 include nylon-6, nylon-6,6, nylon-6,10, nylon-6,12, and the like. These thermoplastic resins can be used individually by 1 type or in combination of 2 or more types.
Among these, the thermoplastic resin contained in the base material layer 21 is preferably a polyolefin resin from the viewpoint of mechanical strength, physical characteristics, chemical characteristics, productivity, and the like.

Furthermore, in the in-mold label 3a, the thermoplastic resin contained in the base material layer 21 is excellent in adhesiveness between the printed layer 11 and the resin molded body 2, and has mechanical strength, physical characteristics, chemical characteristics, and production. From the viewpoint of properties, high-density polyethylene, low-density polyethylene, linear low-density polyethylene, ethylene / α-olefin copolymers, polyethylene resins such as ethylene / vinyl acetate copolymers, or propylene homopolymers, etc. Polypropylene resin is preferred, high density polyethylene, low density polyethylene, linear low density polyethylene, ethylene / α-olefin copolymer, ethylene / vinyl acetate copolymer are more preferred, low density polyethylene, linear low density Polyethylene and ethylene / vinyl acetate copolymer are more preferable, and linear low density polyethylene is particularly preferable. preferable. The ethylene / α-olefin copolymer is preferably a metallocene copolymer copolymerized using a so-called metallocene catalyst.

The base material layer 21 preferably contains a thermoplastic resin having a melting point of 200 ° C. or lower, and more preferably contains a polyolefin resin having a melting point of 200 ° C. or lower. In this case, when the polymer film image is transferred to the base material layer 21 using the toner composition described above, it is easy to form the print layer 11 on the base material layer 21. From the above viewpoint, the melting point of the polyolefin resin contained in the base material layer 21 is preferably 65 ° C. to 200 ° C., more preferably 75 ° C. to 185 ° C., further preferably 85 ° C. to 170 ° C., particularly preferably 90 ° C. ~ 155 ° C. When the melting point of the polyolefin resin constituting the base material layer 21 exceeds the lower limit of the above range, stickiness can be suppressed at room temperature and blocking can be prevented. Moreover, when the melting point of the polyolefin resin constituting the base material layer 21 is lower than the upper limit of the above range, the adhesiveness between the printing layer 11 and the base material layer 21, and the base material layer 21 and the resin molded body 2 There exists a tendency for adhesiveness to improve. In particular, the base material layer 21 is preferably a polyethylene resin having a melting point of 75 ° C. to 140 ° C., and more preferably a metallocene copolymer having a melting point of 75 ° C. to 140 ° C. The melting point is more preferably 85 ° C. to 130 ° C., still more preferably 90 ° C. to 120 ° C.

Furthermore, in the in-mold label 3b, the thermoplastic resin contained in the base material layer 21 is a polyolefin such as high-density polyethylene or propylene resin from the viewpoint of mechanical strength, physical characteristics, chemical characteristics, productivity, and the like. Based resins are preferred. In particular, a propylene-based resin is more preferable, and a propylene homopolymer is more preferable from the viewpoint that the above-described balance of various properties is excellent. Further, the melting point of the thermoplastic resin contained in the base material layer 21 is preferably higher by 10 ° C. or more and more preferably 15 ° C. or higher than the melting point of the resin contained in the printing layer 11. Thereby, the deformation | transformation of the base material layer 21 at the time of sticking the in-mold label 3 to the resin molding 2 can be suppressed. Among such thermoplastic resins, a propylene homopolymer having a melting point of 150 to 170 ° C. is more preferable.

The base material layer 21 is preferably fillerless and substantially free of fillers such as inorganic fine powder and organic fine powder. Here, “substantially does not contain” means that the filler content is 0.0 to 3.0% by mass in terms of solid content with respect to the total amount of the base material layer 21. The amount is more preferably 0.0 to 1.0% by mass, further preferably 0.0 to 0.5% by mass, and particularly preferably 0.0 to 0.01% by mass. When the filler content of the base material layer 21 is in the above range, the base material layer 21 has excellent transparency, and the printed content of the print layer 11 can be clearly visually recognized through the base material layer 21. .

(Additive)
The base material layer 21 may contain additives known in the art as needed in addition to the above-described thermoplastic resin. Examples of the additive contained in the base material layer 21 include a heat stabilizer, an antistatic agent, a plasticizer, an antioxidant, an ultraviolet absorber, and a light stabilizer. The content of the additive in the base material layer 21 is not particularly limited, but is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight with respect to the total amount of the base material layer 21. In addition, although the base material layer 21 may contain a wax, as described above, the printed layer 11 and the base material layer 21 of the present embodiment can be combined with the resin molded body 2 without containing a wax. Sufficient adhesiveness can be obtained. For this reason, it is preferable that the base material layer 21 is waxless which does not contain wax.

(Thickness of base material layer)
The thickness of the base material layer 21 is not particularly limited, but in the in-mold label 3a, it is preferably 20 to 200 μm, more preferably 40 to 180 μm, and still more preferably 50 to 150 μm. In the in-mold label 3b, the thickness of the base material layer 21 is preferably 20 to 200 μm, more preferably 30 to 150 μm, and further preferably 40 to 100 μm. When the thickness of the base material layer 21 is equal to or more than the lower limit of the above range, the in-mold label 3 can be provided with appropriate rigidity to prevent generation of wrinkles when the printing layer 11 is formed. It becomes easy to fix the label at a desired position during insertion. Further, the base material layer 21 is melted together with the printing layer 11 by the heat of the molten resin of the resin molded body 2 at the time of in-mold molding, and the resin molded body 2 and the in-mold label 3 are easily fused, and sufficient adhesiveness is obtained. It tends to be. When the thickness of the base material layer 21 is equal to or less than the upper limit of the above range, it is possible to prevent a decrease in strength of the boundary portion of the in-mold label 3 in the obtained resin molded product, and damage from the label end of the in-mold label 3 In addition, it is possible to prevent the in-mold label 3 from curling and to be easily fixed to the mold. Moreover, the fall of the transparency of the in-mold label 3 can be prevented. In addition, in this specification, the thickness of each layer which comprises the in-mold label 3 or the laminated structure 41 observes a cross section with a microscope, and the whole thickness and observation of the in-mold label 3 or the laminated structure 41 are observed. It means the value obtained by multiplying the ratio of the layer thickness.

(Opacity of substrate layer)
The base material layer 21 is substantially transparent or translucent. The opacity of the base material layer 21 is preferably 40% or less, more preferably 30% or less, still more preferably 20% or less, and particularly preferably 15% or less. In addition, the lower limit of the opacity of the base material layer 21 is usually 0%, preferably 1%. When the opacity of the base material layer 21 is within the above range, the in-mold label 3 having excellent transparency can be obtained. In addition, in a state where the in-mold label 3 is adhered to the resin molded body 2, it is possible to clearly see the printed content of the printed layer 11 from the outside through the base material layer 21. In this specification, the opacity of the base material layer 21 is a value measured according to JIS P 8149: 2000 “Paper and paperboard—Opacity test method (backing of paper) —Diffusion illumination method”. means.

<Ink receiving layer>
Next, the ink receiving layer 31 will be described. The ink receiving layer 31 is a layer constituting the laminated structure 41. In the in-mold label 3 b, the ink receiving layer 31 is a layer that is interposed between the printing layer 11 and the base material layer 21 and receives printing of the printing layer 11. Usually, the thickness of the printing layer 11 is sufficiently thinner than that of the ink receiving layer 31. Therefore, when the printing layer 11 is melted by the heat of the molten resin in in-mold molding, the ink receiving layer 31 is also heated by the heat of the molten resin. And the ink receiving layer 31 is also partially melted, so that the ink receiving layer 31 can contribute to adhesion to the resin molded body 2. As shown in FIG. 10, when the printing layer 11 is not provided on the entire surface of the ink receiving layer 31, that is, provided only on a part of the ink receiving layer 31, the gold layer is formed during in-mold molding. The molten resin constituting the resin molded body 2 in the mold comes into contact with the portion of the ink receiving layer 31 that is not covered with the printing layer 11. At this time, as shown in FIG. 11, the ink receiving layer 31 melted by the heat of the molten resin is fused with the molten resin so as to fill a gap between the partially or intermittently provided printing layers 11. It hardens after cooling and contributes to the adhesion between the resin molded body 2 and the in-mold label 3b.

The ink receiving layer 31 is a layer containing a polyethylene resin. The ink receiving layer 31 is preferably a thermoplastic resin film mainly composed of a polyethylene resin. Here, the main component means a component contained in the ink receiving layer 31 by 50 mass% or more with respect to the total amount of the ink receiving layer 31.

(Polyethylene resin)
Examples of the polyethylene resin contained in the ink receiving layer 31 include high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene, ultra low density polyethylene, ethylene / α-olefin copolymer, ethylene / acetic acid. Vinyl copolymer, ethylene / (meth) acrylic acid copolymer, ethylene / (meth) acrylic acid alkyl ester copolymer, metal salt of ethylene / (meth) acrylic acid copolymer, ethylene / cyclic olefin copolymer However, it is not particularly limited to these. In the above ethylene / α-olefin copolymer, examples of the α-olefin copolymer include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 4-methyl-1 -C3-C10 α-olefins such as pentene. In the ethylene / (meth) acrylic acid alkyl ester copolymer, the alkyl group preferably has 1 to 8 carbon atoms. In addition, these copolymers may be either random copolymers or block copolymers. Examples of the metal in the metal salt of the ethylene / (meth) acrylic acid copolymer include Zn, Al, Li, K, and Na. These can be used alone or in combination of two or more.

Among these, from the viewpoint of excellent adhesion to the printed layer 11 and the resin molding 2, high density polyethylene, low density polyethylene, linear low density polyethylene, ethylene / α-olefin copolymer, ethylene / vinyl acetate copolymer are used. Polymer is preferable, high density polyethylene, linear low density polyethylene, ethylene / α-olefin copolymer, ethylene / vinyl acetate copolymer are more preferable, linear low density polyethylene, ethylene / vinyl acetate copolymer Is more preferable. The ethylene / α-olefin copolymer is preferably a metallocene copolymer copolymerized using a so-called metallocene catalyst. The content of vinyl acetate in the ethylene / vinyl acetate copolymer is not particularly limited, but is preferably 5 to 50% by mass with respect to the total amount of the copolymer. When the content of vinyl acetate is within the above range, the printed layer 11 and the resin molded body 2 can be more strongly bonded, and the transparency tends to be excellent.

The ink receiving layer 31 preferably contains a polyethylene resin having a melting point of 135 ° C. or lower. In this case, when the polymer film image is transferred to the ink receiving layer 31 using the toner composition described above, it is easy to form the printing layer 11 on the ink receiving layer 31. From the above viewpoint, the upper limit of the melting point of the ethylene copolymer contained in the ink receiving layer 31 is preferably 135 ° C, more preferably 130 ° C, still more preferably 125 ° C, particularly preferably 120 ° C, and the lower limit. However, it is preferably 65 ° C, more preferably 75 ° C, still more preferably 85 ° C, and particularly preferably 90 ° C. The melting point of the polyethylene resin contained in the ink receiving layer 31 is preferably 65 ° C. to 135 ° C., more preferably 75 ° C. to 130 ° C., still more preferably 85 ° C. to 125 ° C., and particularly preferably 90 ° C. to 120 ° C. ° C. When the melting point of the polyethylene resin constituting the ink receiving layer 31 exceeds the lower limit of the above range, stickiness can be suppressed at room temperature and blocking can be prevented. Further, the melting point of the polyethylene resin constituting the ink receiving layer 31 is lower than the upper limit of the above range, so that the adhesiveness between the printing layer 11 and the ink receiving layer 31 and the ink receiving layer 31 and the resin molded body 2 are reduced. There exists a tendency for adhesiveness to improve.

Further, as described above, the melting point of the polyethylene resin contained in the ink receiving layer 31 is preferably 10 ° C. or more lower than the melting point of the thermoplastic resin contained in the base material layer 21 and more preferably 15 ° C. or more. preferable. Thereby, the deformation | transformation of the base material layer 21 at the time of sticking the in-mold label 3b to the resin molding 2 can be suppressed. Further, the difference between the melting point of the polyethylene resin contained in the ink receiving layer 31 and the melting point of the thermoplastic resin contained in the base material layer 21 is preferably 100 ° C. or less. Thereby, the blocking in the front | former stage of the sticking process of the in-mold label 3b can be suppressed, and handling of a film becomes easy. Examples of the pre-stage of the in-mold label 3b attaching step include a storage stage and a processing stage.

The ink receiving layer 31 may contain an additive known in the art. Examples of the additive contained in the ink receiving layer 31 include an antistatic agent, a plasticizer, an antioxidant, an ultraviolet absorber, and a light stabilizer. The content of the additive in the ink receiving layer 31 is not particularly limited, but is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass with respect to the total amount of the ink receiving layer 31. The ink receiving layer 31 may contain a wax. However, as described above, the printing layer 11 and the ink receiving layer 31 of the present embodiment can be combined with the resin molded body 2 without containing a wax. Sufficient adhesiveness can be obtained. For this reason, it is preferable that the ink receiving layer 31 is waxless without containing wax.

(Ink-receiving layer thickness)
The thickness of the ink receiving layer 31 is not particularly limited, but the lower limit is preferably 0.1 μm, more preferably 3 μm, still more preferably 5 μm, particularly preferably 10 μm, while the upper limit is preferably 30 μm, more Preferably it is 25 micrometers, More preferably, it is 20 micrometers. The thickness of the ink receiving layer 31 is preferably 0.1 to 30 μm, more preferably 3 to 25 μm, still more preferably 5 to 20 μm, and particularly preferably 10 to 20 μm. When the thickness of the ink receiving layer 31 is not less than the lower limit of the above range, the ink receiving layer 31 is melted together with the printing layer 11 by the heat of the molten resin of the resin molded body 2 during in-mold molding, and the resin molded body 2 And the in-mold label 3b are easily fused, and sufficient adhesiveness tends to be obtained. When the thickness of the ink receiving layer 31 is equal to or less than the upper limit of the above range, the curling of the in-mold label 3b is prevented, and the formation of the printing layer 11 on the ink receiving layer 31 and the fixing to the mold are easy. It becomes.

<Laminated structure>
Subsequently, the laminated structure 41 will be described. The laminated structure 41 includes the base material layer 21 and the ink receiving layer 31. The laminated structure 41 functions as a printing base film for providing the printing layer 11 on the surface on the ink receiving layer 31 side. Further, in a state where the printed layer 11 is heat-sealed to the resin molded body 2, the laminated structure 41 exists on the surface side of the in-mold label 3 b and thus functions as a protective layer for the printed layer 11.

(Thickness of laminated structure)
The thickness of the laminated structure 41 is appropriately set according to the thicknesses of the base material layer 21 and the ink receiving layer 31 and is not particularly limited, but is preferably 30 to 200 μm, more preferably 40 to 180 μm, and still more preferably 50. ~ 150 μm. When the thickness of the laminated structure 41 is within the above range, desired performances of the base layer 21 and the ink receiving layer 31 are exhibited, and sufficient adhesion between the printed layer 11 and the resin molded body 2 is obtained. In addition, it is possible to protect the printing layer 11 and to provide friction resistance.

(Opacity)
The opacity of the laminated structure 41 is preferably 40% or less, more preferably 30% or less, still more preferably 20% or less, and particularly preferably 15% or less. Further, the lower limit of the opacity of the laminated structure 41 is usually 0%, preferably 1%. Preferably it is 0 to 40%, more preferably 0 to 30%, still more preferably 0 to 20%, particularly preferably 0 to 15%. When the opacity of the laminated structure 41 is within the above range, the in-mold label 3b having excellent transparency can be obtained. In addition, in a state where the in-mold label 3 b is adhered to the resin molded body 2, the printed content of the printed layer 11 can be clearly seen from the outside through the laminated structure 41. In this specification, the opacity of the laminated structure 41 is a value measured according to JIS P 8149: 2000 “Paper and paperboard—Opacity test method (backing of paper) —Diffusion illumination method”. means.

<Base Layer, Ink Receiving Layer, and Laminate Structure Forming Method>
The method for forming the base material layer 21 is not particularly limited, and various known methods can be used. Specific examples include cast molding in which molten resin is extruded into a sheet using a single-layer or multilayer T-die or I-die connected to a screw-type extruder, and the molten resin is extruded into a tube using a circular die. Inflation molding in which the air pressure is expanded, calender molding in which a kneaded material is rolled with a plurality of hot rolls and processed into a sheet, and rolling molding are exemplified. The base material layer 21 itself may have a single-layer structure or a multilayer structure of two or more layers, but is preferably a single-layer structure from the viewpoint of preventing curling.
The ink receiving layer 31 can also be formed by a method similar to the method for forming the base material layer 21 described above.

As a method for obtaining the laminated structure 41 by laminating the base material layer 21 and the ink receiving layer 31, at least one of coextrusion molding in which both molten resins are laminated in a die, the base material layer 21 and the ink receiving layer 31 is used. The substrate layer 21 and the ink receiving layer 31 obtained by film forming in advance, extrusion lamination molding in which the heat-melted thermoplastic resin composition constituting the other layer is extruded and laminated, Examples include dry laminate molding or wet laminate molding in which layers are laminated via an adhesive layer. When the laminated structure 41 is formed by these methods, the thickness of the obtained ink receiving layer 31 is preferably 3 to 30 μm.

The laminated structure 41 can also be obtained by applying the resin constituting the ink receiving layer 31 as a paint to the base material layer 21 by a method described later and drying it as necessary. This paint can be prepared by dissolving the resin constituting the ink receiving layer 31 in a solvent or dispersing it in a solvent. The resin is not particularly limited as long as it is a polyethylene resin contained in the ink receiving layer 31 described above. Among them, an ethylene / α-olefin copolymer and an ethylene / vinyl acetate copolymer are preferable. Although it does not specifically limit as a solvent, Water, toluene, acetone, methyl ethyl ketone, methanol, ethanol etc. can be used conveniently. The coating method is not particularly limited, and known coating methods such as a die coater, bar coater, roll coater, lip coater, gravure coater, spray coater, blade coater, reverse coater, air knife coater and the like can be used. . When the laminated structure 41 is formed by these methods, the thickness of the obtained ink receiving layer 31 is preferably 0.1 to 10 μm.

Among these, by using a multi-layer T die connected to a screw type extruder, by laminating the molten resin of the base material layer 21 and the ink receiving layer 31 in the same die, by coextrusion cast molding that is extruded into a sheet shape, A method of obtaining the laminated structure 41 by simultaneously laminating and forming both layers is preferable. This method is simple in terms of process, and is a coextruded film having an adhesive strength that the base material layer 21 and the ink receiving layer 31 do not easily peel off in a post-processing step such as formation or cutting of the printing layer 11. Since it is obtained, it is preferable.

The substrate layer 21, the ink receiving layer 31, and the laminated structure 41 may be non-stretched (unstretched) films that are not stretched, or may be stretched films by stretching in at least a uniaxial direction. The unstretched film is further excellent in transparency and shape followability to a molded product. On the other hand, the stretched film is more excellent in transparency, lightness, and thickness uniformity due to thinning.

The in-mold label 3 of the present embodiment may be subjected to surface oxidation treatment on the base material layer 21 or the ink receiving layer 31 as necessary. The surface of the film after molding has a relatively low surface free energy, and the surface free energy of the surface of the film can be improved by subjecting the surface of the film to surface oxidation treatment. As a result, the transferability of the toner composition is improved, so that the adhesion between the printing layer 11 and the base material layer 21 or the ink receiving layer 31 is improved. From such a viewpoint, the surface oxidation treatment is preferably performed on the layer on which the printing layer 11 is provided. For example, as shown in FIG. 2, when the printing layer 11 is provided on the base material layer 21, the base material layer 21 may be subjected to surface oxidation treatment. Alternatively, as shown in FIG. 9, when the printing layer 11 is provided on the ink receiving layer 31, the surface of the laminated structure 41 on the ink receiving layer 31 side may be subjected to surface oxidation treatment. The transferability of the toner composition may be improved by controlling the water contact angle on the surface of the base material layer 21 or the ink receiving layer 31. Examples of the surface oxidation treatment include corona discharge treatment, flame treatment, plasma treatment, glow discharge treatment, and ozone treatment. Among these, it is preferable to use corona discharge treatment or plasma treatment as the surface oxidation treatment. Alternatively, the base layer 21 or the ink receiving layer 31 may be subjected to frame processing. Moreover, the in-mold label 3 may form a surface coating layer on the base material layer 21 or the ink receiving layer 31 for the same purpose as the surface oxidation treatment described above.

<Protective layer>
As described above, the base material layer 21 also functions as a protective layer for the printing layer 11, but the in-mold label 3 a has improved lightness, water resistance, gas resistance, friction resistance, and other fastness properties. In addition, a protective layer made of a resin film may be further provided on the surface of the base material layer 21 opposite to the printed layer 11. Further, the in-mold label 3b is provided with a protective film made of a resin film on the surface of the laminated structure 41 on the base material layer 21 side in order to improve fastness such as light resistance, water resistance, gas resistance, and friction resistance. A layer may be provided. The resin constituting the protective layer is not particularly limited, but the same thermoplastic resin as that used in the base material layer 21 described above can be used. For example, polyolefin resin, polystyrene resin, polyester resin, polycarbonate Examples thereof include resins and polyamide resins. As a polyolefin-type resin, the thing similar to resin used by the base material layer 21 mentioned above can be used. The thickness of the protective layer is not particularly limited, but is preferably 5 to 100 μm, more preferably 10 to 50 μm. Various methods can be adopted as means for providing the protective layer, and are not particularly limited. Means for layering the surface of the base material layer 21 or the laminated structure 41 on the base material layer 21 side using a dry laminating method or a thermal laminating method, the base material layer 21, or the base material layer 21 and the ink receiving layer What is necessary is just to select suitably from well-known means, such as the method of extrusion laminating with 31, the method of coating a thermoplastic resin.

<In-mold label>
The in-mold label 3 of this embodiment is suitably used as a label attached to the resin molded body 2 in in-mold molding. At this time, the in-mold label 3 may be set in advance in the mold so that the surface on the base material layer 21 side is in contact with the inner wall of the mold.

The in-mold label 3 a can be manufactured by first forming the base material layer 21 and then forming the printing layer 11 on the base material layer 21. At this time, it is preferable to provide the printing layer 11 on one main surface of the base material layer 21 so that the printing layer 11 directly contacts. That is, the base material layer 21 and the printing layer 11 are laminated without interposing another layer (for example, an adhesive layer or a conventional heat seal layer) between the base material layer 21 and the printing layer 11. It is preferable from the viewpoint of curling suppression, productivity and cost of the in-mold label 3 to be obtained.

Alternatively, the in-mold label 3b can be manufactured by first forming the laminated structure 41 and then forming the printing layer 11 on the surface of the laminated structure 41 on the ink receiving layer 31 side. That is, it is preferable to provide the ink receiving layer 31 between the base material layer 21 and the printing layer 11 from the viewpoint of improving the adhesiveness between the printing layer 11 and the base material layer 21 via the ink receiving layer 31.

[2. Labeled container]
The labeled container 1 can be manufactured by sticking the in-mold label 3 to the resin molded body 2 by in-mold molding (in-mold labeling). At the time of in-mold molding, the surface on the printed layer 11 side is heat-sealed to the wall surface of the resin molded body 2, whereby the labeled container 1 can be integrally molded. The labeled container 1 is an example of an in-mold molded body that is a resin molded product by in-mold molding to which an in-mold label 3 is attached. The in-mold molded body is a three-dimensional molded body that forms a space, for example, a hollow molded body such as a bottle, a tank, or a squeeze container; a molded body having an opening surface such as a tray, a cup, or a container; What has shapes, such as a hollow molded object formed in the shape, is mentioned.

<Resin molding>
The resin molded body 2 according to the present embodiment is a hollow molded product including a thermoplastic resin. The thermoplastic resin constituting the resin molded body 2 is not particularly limited as long as it is a material that can be molded into a desired shape. Examples of the thermoplastic resin constituting the resin molded body 2 include polyolefin resins such as polyethylene resins and polypropylene resins; polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polybutylene succinate, and polylactic acid; aromatic polycarbonates, Examples thereof include polycarbonate resins such as aliphatic polycarbonates; polystyrene resins and the like, but are not particularly limited thereto. These can be used alone or in combination of two or more. Among these, from the viewpoints of transparency, moldability, and adhesiveness with the in-mold label 3, a polyolefin resin is preferable, and a polyethylene resin is more preferable. Examples of the polyethylene resin include high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene, ultra-low density polyethylene, and ethylene / α-olefin copolymer. Among these, high density polyethylene and linear low density polyethylene are preferable, and linear low density polyethylene is more preferable. Further, as described above, the melting point of the thermoplastic resin constituting the resin molded body 2 is preferably 5 ° C. or higher, more preferably 10 ° C. or higher than the melting point of the resin used for the printing layer 11.

<In-mold molding>
In-mold molding is performed by placing the in-mold label 3 at a predetermined position in the mold so that the surface on the base material layer 21 side is in contact with the inner wall of the mold, and further injecting molten resin into the mold. . Thereby, the labeled container 1 to which the in-mold label 3 is stuck simultaneously with the molding of the resin molded body 2 is obtained. Examples of such in-mold molding include injection molding, blow molding such as direct blow molding and stretch blow molding. Among these, blow molding is preferable.

After the in-mold label 3 is placed in the mold, the in-mold label 3 and the resin molded body 2 are integrally formed. Thus, a molded product having a good external appearance decorated with the in-mold label 3 can be easily obtained. Here, “in-mold” the in-mold label 3 and the resin molded body 2 means that a part of the resin component constituting the resin molded body 2 and a part of the resin component constituting the printed layer 11 of the in-mold label 3. Means a state of being bonded in a mixed state at these interfaces.

(In-mold label burial)
In the labeled container 1, the in-mold label 3 is adhered to the resin molded body 2 by in-mold molding. Therefore, at least part of the thickness direction of the in-mold label 3 is buried in the outer wall of the resin molded body 2. Therefore, the thickness dimension of the in-mold label 3 is set to “T ₁ ”, and the height dimension (thickness-direction dimension) of the in-mold label 3 that forms a step portion on the outer side with respect to the outer surface of the outer wall of the resin molded body 2. the if you put a "T _2", a relationship that satisfies the inequality "T _1> T _2". In the case of a blow molding method using a preform, the inequality “T ₁ > T ₂ ” is easily satisfied. The entire thickness direction of the in-mold label 3 may be buried in the outer wall of the resin molded body 2 (for example, the outer surface of the in-mold label 3 and the outer surface of the resin molded body 2 are in the same plane), In this case, “T ₂ = 0”. In the case of direct blow molding, the equation “T ₂ = 0” is easily satisfied.

The degree to which the in-mold label 3 is buried in the outer wall of the resin molded body 2 can be represented by the burying rate. When the height dimension (dimension in the thickness direction) of the in-mold label 3 embedded in the resin molded body 2 with respect to the outer surface of the outer wall of the resin molded body 2 is “T ₃ ”, the burial rate (%) is It is obtained by “T ₃ / T ₁ × 100”. The burial rate is preferably 1 to 100%, more preferably 10 to 95%, still more preferably 30 to 90%, and particularly preferably 50 to 80%. When the burial ratio is within the above range, the overmolding of the in-mold label 3 from the resin molded body 2 is suppressed, and the adhesion between the in-mold label 3 and the resin molded body 2 tends to be strengthened.

The depth at which the in-mold label 3 is buried in the outer wall of the resin molded body 2 can be appropriately set according to the thickness of the in-mold label 3, but is not particularly limited, but is preferably 5 to 200 μm, more preferably Is 10 to 150 μm, more preferably 50 to 100 μm. In the present specification, the above-described thickness direction dimensions T ₁ , T ₂ , and T ₃ mean values measured by observing the labeled container 1 with a microscope.

(Adhesive strength)
In the labeled container 1, the adhesive strength between the in-mold label 3 and the resin molded body 2 may be set as appropriate according to the required performance and the like, and is not particularly limited. It is 2000 gf / 15 mm, more preferably 200 to 1700 gf / 15 mm, and still more preferably 500 to 1500 gf / 15 mm. In the in-mold label 3b, the adhesive strength is preferably 100 to 2000 gf / 15 mm, more preferably 400 to 1500 gf / 15 mm, and still more preferably 600 to 1400 gf / 15 mm. When the adhesive strength is within the above range, the in-mold label 3 can be adhered to the friction, vibration, and impact received by the labeled container 1. In this specification, the adhesive strength means a value measured according to JIS K6854-3: 1999 “Adhesive—Peeling peel strength test method—Part 3: T-type peel”.

(Area ratio)
The ratio of the total area of the in-mold label 3 to the surface area of the labeled container 1 (area ratio (%)) is not particularly limited, but is preferably 5% to 90%, more preferably 20 to 80%, and more preferably 30 to 70%. Is more preferable. In particular, when the labeled container 1 is a bottle-shaped hollow molded body, it is preferably 5% to 50%, more preferably 10 to 40%, and further preferably 15 to 30%. When the area ratio is within the above range, the display function of the in-mold label 3 can be expressed.

[3. Action, effect]
The in-mold label 3 of the present embodiment includes a printed layer 11 provided on the base material layer 21 or the laminated structure, and the printed layer 11 is heat-sealed to the wall surface of the resin molded body 2, thereby providing a container with a label. 1 is formed. At this time, since the printing layer 11 is protected by the base material layer 21 or the laminated structure and is not exposed to the outside, the friction resistance and water resistance of the printing layer 11 are improved. Furthermore, when the opacity of the base material layer 21 or the laminated structure is 40% or less, the printing content exhibited by the color material contained in the printing layer 11 is transmitted from the outside through the base material layer 21 or the laminated structure. It can be visually recognized. Furthermore, when the printing layer 11 contains an ethylene copolymer, the printing layer 11 itself functions as a heat seal layer, and sufficient adhesion between the in-mold label 3 and the resin molded body 2 is obtained. As described above, the in-mold label 3 and the labeled container 1 according to the present embodiment allow the in-mold label 3 and the resin to be protected while enabling protection and visual recognition of the print contents displayed on the print layer 11 in contact with the resin molded body 2. It also has adhesiveness with the molded body 2. In addition, since the in-mold label 3 of the present embodiment employs the above-described configuration, curling is unlikely to occur due to the influence of temperature or humidity change. This is also significant in that occurrence of appearance defects such as misalignment and wrinkles is easily suppressed.

[4. Application]
The in-mold molded product of the present invention includes, for example, household detergent, bathtub detergent, toilet bowl detergent, car wash detergent, facial cleanser, liquid soap, shampoo, rinse, deodorant, liquid bath agent, iron paste, Containers for chemicals (bottles) used for alcohol for sterilization, wax for polishing, insecticides, etc .; containers for foods (bottles) used for soft drinks, sake, soy sauce, oil, sauce, sauces, dressings, etc .; containers for cosmetics (bottles) ); Pharmaceutical containers (bottles); squeeze containers used for spreads such as jam, margarine, peanut butter, ketchup, mayonnaise; containers for ice cream, yogurt, etc .; containers for laundry detergent, dishwashing detergent, wet tissue, etc .; smartphone cases , Cases and exterior parts for electronic devices such as smartphone covers; can be used as hollow molded products such as models, dolls, and toys It is.

Hereinafter, the present invention will be specifically described with reference to examples. In addition, the material, usage-amount, ratio, the processing content, processing procedure, etc. which are shown in the following Examples can be suitably changed unless it deviates from the meaning of this invention. Therefore, the present invention is not limited to the following examples.

[Evaluation method]
The evaluation of the in-mold label and the labeled container obtained in Production Example a group, Example a group, and Comparative Example a group, and Production Example b group, Example b group, and Comparative Example b group are as follows. I went there.

<Thickness>
In accordance with JIS K 7130: 1999 “Plastics—Film and Sheet—Thickness Measurement Method”, the thickness of the base material layer was measured using a constant pressure thickness measuring instrument (manufactured by Teclock Co., Ltd., device name: PG-01J). And the thickness of the whole laminated structure was measured.
The thickness of each layer in the laminated structure was measured by the following procedure. First, the laminated structure serving as the measurement target sample was cooled to a temperature of −60 ° C. or lower using liquid nitrogen. Subsequently, the sample to be measured after cooling is placed on a glass plate, a razor blade (product name: Proline Blade, manufactured by Chic Japan Co., Ltd.) is applied to the sample to be measured at a right angle, and the sample to be measured is measured. A sample for cross-sectional measurement was created by cutting the. Next, the cross section of this cross section measurement sample was observed using a scanning electron microscope (manufactured by JEOL Ltd., device name: JSM-6490). At this time, the boundary line was discriminated based on the difference in appearance due to the difference in composition from the observed image, and the ratio of the thickness of the layer to be measured to the thickness of the entire film was determined. Thereafter, the thickness of the layer to be measured was obtained by multiplying the overall thickness by the ratio of the layer thicknesses determined by observing the sample for cross-sectional measurement.

<Opacity>
In accordance with JIS P 8149: 2000, the opacity of the base material layer and the laminated structure was measured. A test piece having a size of 100 mm × 100 mm was prepared from the base material layer and the laminated structure, and the opacity at each of the three locations was set to 1 using a color meter (manufactured by Suga Test Instruments Co., Ltd., device name: SM color computer). Measurement was performed once, and the average value of all measurement data was calculated. Regarding the base material layer, the transparency was determined by setting the opacity of 40% or less as transparent (◯) and the opacity exceeding 40% as opaque (x).

<Adhesive strength>
Based on JIS K6854-3: 1999, the adhesive strength between the resin molded body and the in-mold label was measured. The in-mold label attached to the resin molded body was cut to a width of 15 mm, and the adhesion strength between the in-mold label and the resin molded body was measured using a tensile tester (manufactured by Shimadzu Corporation, device name: Autograph AGS- D-type) and T-type peeling at a tensile speed of 300 mm / min.

<Abrasion resistance>
The in-mold label affixed to the resin molded product is cut to a width of 25 mm and attached to a Gakushin type dyeing friction fastness tester (Suga Test Instruments Co., Ltd., equipment name: friction tester type II), white cotton cloth Kanakin No. 3 The in-mold label side was subjected to a friction test 100 times with a load of 500 g, and the presence or absence of ink dropout was visually evaluated and judged according to the following criteria.
○: Good (no ink drop off is observed)
Δ: Slightly poor (scratches on the ink surface)
X: Defect (ink drops off)

<Visibility>
The appearance of the printed portion of the in-mold label attached to the resin molded body (characters printed with black ink in a 6 pt font) was visually confirmed, and Example a group, Comparative Example a group, and Example b About the group and the comparative example b group, it determined on the following references | standards, respectively.
(Example a group and Comparative example a group)
○: Good (can be visually recognized without significant change in character color and density after molding)
Δ: Slightly poor (character color and density slightly change after molding)
X: Defect (the color and density of characters appear clearly light after molding)
XX: Extremely bad (characters are not visible after molding)
(Example b group and Comparative example b group)
○: Good (characters can be visually recognized after molding)
X: Defect (characters are not visible after molding)

[Production example a group, Example a group, and Comparative example a group (two-layer type)]
[Manufacture of base material layer]
Table 1 shows the details of the materials used in Production Example a group, Example a group, and Comparative Example a group.

<Production example a1 (base material layer)>
In Production Example a1 of the base material layer, metallocene polyethylene (manufactured by Nippon Polyethylene Co., Ltd., Kernel KF360T) was used as the resin A1 constituting the base material layer. Resin A1 was kneaded in an extruder set at 230 ° C. Then, it supplied to one coextrusion die set to 250 degreeC, extruded to the sheet form, this was cooled with the cooling device, and the base material layer of manufacture example a1 which consists of one layer was obtained. The base material layer of Production Example a1 had a thickness of 80 μm.

<Production Examples a2 to a5 (base material layer)>
In Production Example a1 of the base material layer described above, Production Example a2 was carried out in the same manner as Production Example a1, except that resins A2 to A5 shown in Table 1 were used instead of resin A1 constituting the base material layer. A substrate layer of .about.a5 was produced. In all of the base material layers of Production Examples a2 to a5, the total thickness of the base material layer was 80 μm.

<Production Example a6 (base material layer)>
In the production example a1 of the base material layer described above, the same procedure as in Production Example a1 was performed except that the resin composition A6 containing calcium carbonate described in Table 1 was used instead of the resin A1 constituting the base material layer. The base material layer of Production Example a6 was produced. In the base material layer of Production Example a6, the thickness of the whole base material layer was 80 μm.

[Production of in-mold labels]
<Example a1 (in-mold label)>
In Example a1 of an in-mold label, an ethylene / methacrylic acid copolymer (made by Hewlett-Packard Indigo BV, trade name: HP ElectroInk Black) containing a coloring material was used as the toner composition B1. This toner composition B1 was printed on the base material layer of Production Example a1 using an HP Indigo WS6800 printing press (Hewlett-Packard Inc.) to form a printed layer. Punching was performed after printing to obtain an in-mold label of Example a1. At this time, printing was performed in an environment of a temperature of 23 ° C. and a relative humidity of 50%. The printing conditions were a blanket temperature of 105 ° C. and a transfer pressure of 200 kg. Further, solid printing with an ink density (halftone dot area ratio) of 100% was performed. As shown in FIG. 2, the layer configuration of the in-mold label 3 a of Example a1 includes a printing layer 11 and a base material layer 21, and the printing layer 11 is provided over the entire surface of the base material layer 21. It corresponds to an aspect. In addition, as shown in FIG. 7, the in-mold label 3a of Example a1 forms the container 100 with a label, when the base material layer 21 is heat-sealed to the wall surface of the resin molded body 2. . At this time, the printing layer 11 is exposed outward.

<Example a2 (in-mold label)>
In Example a1 of the above-described in-mold label, the printing was performed in the same manner as in Example a1, except that printing with a dot area ratio of 50% was performed instead of solid printing with a dot area ratio of 100%. An in-mold label a2 was obtained. As shown in FIG. 3, the layer configuration of the in-mold label 3 a of Example a2 includes a printing layer 11 and a base material layer 21, and the printing layer 11 is partially or intermittently provided on one surface of the base material layer 21. It corresponds to the aspect provided.

<Example a3 (in-mold label)>
In Example a2 of the in-mold label described above, except that printing was performed on the base material layer of Production Example a2 instead of the base material layer of Production Example a1, the same procedure as in Example a2 was performed. A mold label was obtained. The layer configuration of the in-mold label in Example a3 corresponds to the same layer configuration as in Example a2.

<Examples a4 to a6 (in-mold label)>
In Example a1 of the in-mold label described above, Example 1 was performed in the same manner as Example a1 except that printing was performed on the base material layers of Production Examples a3 to a5 instead of the base material layer of Production Example a1. In-mold labels a4 to a6 were obtained. The layer configuration of the in-mold label in Examples a4 to a6 corresponds to the same layer configuration as in Example a1.

<Comparative Example a1 (Use of in-mold label / oxidized polymerization type ink)>
In Example a1 of the in-mold label described above, a rosin-modified phenolic resin (oxidation polymerization type) containing a color material (Oxide Polymerization Type) (T & K TOKA Corporation) was used as the ink composition B2 instead of the toner composition B1 constituting the printing layer. Example a1 except that this ink composition B2 was printed using an offset printing machine (manufactured by Ryobi Co., Ltd., equipment name: RYOBI3300CR) using a product manufactured by Trade Name: BEST ONE Best SP). The in-mold label of Comparative Example a1 was obtained. As shown in FIG. 5, the layer configuration of the in-mold label 102 of Comparative Example a1 includes an ink print layer 111 containing a rosin-modified phenol resin containing a color material, and a base material layer 21. This corresponds to an aspect in which the ink printing layer 111 is provided over the entire surface of the ink. The in-mold label 102 of Comparative Example a1 forms the labeled container 101 by thermally fusing the ink print layer 111 to the wall surface of the resin molded body 2.

<Comparative example a2 (in-mold label / photopolymerization type ink use)>
In Example a1 of the in-mold label described above, an acrylic ester oligomer (photopolymerization type) containing a color material (manufactured by T & K TOKA Co., Ltd.) was used as the ink composition B3 instead of the toner composition B1 constituting the printing layer. The product was manufactured in the same manner as in Example a1, except that this ink composition B3 was printed using an offset printing machine (manufactured by Ryobi Co., Ltd., device name: RYOBI3300CR). The in-mold label of Comparative Example a2 was obtained. As shown in FIG. 6, the layer configuration of the in-mold label 104 of Comparative Example a2 includes an ink print layer 112 containing an acrylic ester oligomer containing a coloring material, and a base material layer 21. This corresponds to an aspect in which the ink printing layer 112 is provided over the entire surface. The in-mold label 104 of the comparative example a2 forms the labeled container 103 by thermally fusing the ink print layer 112 to the wall surface of the resin molded body 2.

<Comparative example a3 (in-mold label / calcium carbonate-containing)>
In Example a1 of the in-mold label described above, except that printing was performed on the base material layer of Production Example a6 instead of the base material layer of Production Example a1, the same procedure as in Example a1 was performed, and A mold label was obtained. As shown in FIG. 8, the layer configuration of the in-mold label 106 of the comparative example a3 includes the printing layer 11 and the base material layer 121 containing calcium carbonate, and the printing layer 11 covers the entire surface of the base material layer 121. It corresponds to the aspect provided. The in-mold label 106 of the comparative example a3 forms the labeled container 105 by thermally fusing the printing layer 11 to the wall surface of the resin molded body 2.

[Manufacture of labeled molded products]
<Example a11 (molded article with label)>
Using a high-density polyethylene (manufactured by Nippon Polyethylene Co., Ltd., trade name: Novatec HD HJ490) as the molding resin C1, it was carried out on one side of a mold for molding a test piece of length 130 mm × width 150 mm × thickness 2 mm. The in-mold label (70 mm × 90 mm) of Example a1 was manually inserted so that the base layer side was in contact with the mold, and this in-mold label was sucked and fixed to the mold. Next, the mold was clamped, and injection molding of the resin C1 melted at 230 ° C. was performed under an injection pressure of 750 kgf / cm ² by an injection molding machine (manufactured by Niigata Steel). After molding, the mold was cooled, the mold was opened, and the labeled test piece of Example a11 was obtained.
This test piece has a structure equivalent to that shown in FIG. About this test piece, the adhesive strength of the label, friction resistance, and visibility were evaluated. From the evaluation results using the test pieces, it can be seen that the in-mold label of the present invention can be suitably used for a labeled container.

<Examples a12 and a13 (molded products with labels)>
In the above-mentioned Example a11, it replaced with resin C1 which comprises a resin molding, and it carried out similarly to Example a11 except having used resin C2, C3 of Table 1, respectively, and is equivalent to having shown in FIG. The labeled test pieces of Examples a12 and a13 having the structure:

<Example a14 (molded article with label)>
In Example a11 described above, except that the in-mold label of Example a2 was used instead of the in-mold label of Example a1, the same procedure as in Example a11 was performed and the structure shown in FIG. 4 was the same. Then, a labeled test piece of Example a14 was obtained.

<Examples a15 and a16 (molded products with labels)>
In Example a14 described above, the procedure was the same as Example a14 except that the resins C2 and C3 shown in Table 1 were used instead of the resin C1 constituting the resin molded body, and the same as shown in FIG. The labeled test pieces of Examples a15 and a16 having the structure:

<Example a17 (molded article with label)>
In Example a16 described above, except that the in-mold label of Example a3 was used instead of the in-mold label of Example a2, the same procedure as in Example a16 was performed, and the structure equivalent to that shown in FIG. 4 was obtained. Thus, a labeled test piece of Example a17 was obtained.

<Examples a18 to a20 (molded article with label)>
In Example a13 described above, the same procedure as in Example a13 was performed, except that the in-mold labels of Examples a4 to a6 were used instead of the in-mold label of Example a1, and the same as shown in FIG. The labeled test pieces of Examples a18 to a20 having the structure were obtained.

<Comparative example a11 (molded article with label)>
In Example a13 described above, except that the in-mold label of Comparative Example a1 was used instead of the in-mold label of Example a1, the same procedure as in Example a13 was performed and the structure shown in FIG. 5 was equivalent. Thus, a labeled test piece of Comparative Example a11 was obtained.

<Comparative Example a12 (molded product with label)>
In Example a13 described above, except that the in-mold label of Comparative Example a2 was used instead of the in-mold label of Example a1, the same procedure as in Example a13 was performed and the structure shown in FIG. 6 was the same. Thus, a labeled test piece of Comparative Example a12 was obtained.

<Comparative example a13 (molded article with label)>
In Example a13 described above, instead of manually inserting the in-mold label of Example a1 so that the base layer side is in contact with the mold, the in-mold label of Example a1 is in contact with the mold. Thus, a labeled test piece of Comparative Example a13 having the same structure as that shown in FIG. 7 was obtained except that it was manually inserted.

<Comparative Example a14 (molded article with label)>
In Example a13 described above, except that the in-mold label of Comparative Example a3 was used instead of the in-mold label of Example a1, the same procedure as in Example a13 was performed and the structure shown in FIG. 8 was equivalent. Thus, a labeled test piece of Comparative Example a14 was obtained.

[Evaluation]
Table 2 shows the configuration of the labeled molded product and the evaluation results.

As is apparent from Table 2, all of the labeled molded articles of Examples a11 to a20 using the in-mold labels of Examples a1 to a6 provided with a printing layer containing a color material and an ethylene copolymer. Adhesive strength is 200gf / 15mm or more, and has practically sufficient adhesiveness. In addition, these molded articles with labels are excellent in friction resistance and visibility, and the resin content can be protected and visually recognized on the side where the in-mold label and the resin molded body come into contact with each other. It turns out that it has what has adhesiveness with a molded object. In Examples a11 to a16 and a18 to a20, the adhesive strength of 500 gf / 15 mm or more is exhibited by heat-sealing through the printed layer, and the compatibility between the resins is high. It was confirmed that sufficient adhesiveness was also exhibited in Example a17, which is considered to be low. Furthermore, from the results of Examples a14 to a17, it can be seen that good adhesion can be obtained even when the printing layer is partially provided.

On the other hand, the labeled molded products of Comparative Examples a11 and a12 using the in-mold labels of Comparative Examples a1 and a2 are obtained by heat-sealing the ink print layer to the wall surface of the resin molded body, but have sufficient adhesive strength. Was not obtained. Further, the labeled molded product of Comparative Example a13 had poor wear resistance because the printed layer was disposed on the outer surface of the labeled molded product and the printed content was exposed. Moreover, the labeled molded product of Comparative Example a14 using the in-mold label of Comparative Example a3 had poor transparency because the substrate layer contained a large amount of calcium carbonate, and the visibility was extremely poor.

[Manufacturing example b group, Example b group, and Comparative example b group (three-layer type)]
[Manufacture of laminated structure]
Table 3 shows details of materials used in Production Example b group, Example b group, and Comparative Example b group.

<Production example b1 (laminated structure)>
In Production Example b1 of the laminated structure, a propylene homopolymer (manufactured by Nippon Polypro Co., Ltd., trade name: Novatec PP FY4) was used as the resin D1 constituting the base material layer. Further, as the resin E1 constituting the ink receiving layer, metallocene polyethylene (manufactured by Nippon Polyethylene Co., Ltd., trade name: Kernel KS340T) was used. These resin D1 and resin E1 were kneaded in an extruder set at 230 ° C., respectively. Then, it is supplied to a single coextrusion die set at 250 ° C., and is laminated into two layers of D1 / E1 in the die and extruded into a sheet shape. A laminated structure of b1 was obtained. In the laminated structure of Production Example b1, the total thickness of the laminated structure was 79 μm, the thickness of the base material layer was 67 μm, and the thickness of the ink receiving layer was 12 μm.

<Production Examples b2 to b5 (laminated structure)>
In Production Example b1 of the laminated structure described above, Production Example b2 was carried out in the same manner as Production Example b1, except that resins E2 to E5 shown in Table 3 were used instead of resin E1 constituting the ink receiving layer. A laminated structure of .about.b5 was produced. In each of the laminated structures of Production Examples b2 to b5, the total thickness of the laminated structure was 79 μm, the thickness of the base material layer was 67 μm, and the thickness of the ink receiving layer was 12 μm.

<Production Example b6 (Laminated Structure)>
In the production example b1 of the laminated structure described above, in place of the resin D1 constituting the base material layer, except that the resin composition D2 containing calcium carbonate described in Table 3 was used, the production was performed in the same manner as in Production Example b1, The laminated structure of Production Example b6 was produced. In the laminated structure of Production Example b6, the total thickness of the laminated structure was 79 μm, the thickness of the base material layer was 67 μm, and the thickness of the ink receiving layer was 12 μm.

[Production of in-mold labels]
<Example b1 (in-mold label)>
In Example b1 of an in-mold label, an ethylene / methacrylic acid copolymer (made by Hewlett-Packard Indigo BV, trade name: HP ElectroInk Black) containing a coloring material was used as the toner composition B1. This toner composition B1 was printed on the ink receiving layer side of the laminated structure of Production Example b1 using an HP Indigo WS6800 printer (Hewlett-Packard Inc.) to form a printed layer. Punching was performed after printing to obtain an in-mold label of Example b1. At this time, printing was performed in an environment of a temperature of 23 ° C. and a relative humidity of 50%. The printing conditions were a blanket temperature of 105 ° C. and a transfer pressure of 200 kg. Further, solid printing with an ink density (halftone dot area ratio) of 100% was performed. As shown in FIG. 9, the layer configuration of the in-mold label 3 b of Example b1 includes the printing layer 11 / the ink receiving layer 31 / the base material layer 21 in this order, and the printing layer over the entire surface of the ink receiving layer 31. 11 corresponds to the aspect in which 11 is provided.

<Example b2 (in-mold label)>
In Example b1 of the above-described in-mold label, the printing was performed in the same manner as Example b1 except that printing with a dot area ratio of 50% was performed instead of solid printing with a dot area ratio of 100%. An in-mold label b2 was obtained. As shown in FIG. 10, the layer configuration of the in-mold label 3 b of Example b2 has a printing layer 11 / an ink receiving layer 31 / a base layer 21 in this order, and is partially or intermittent on one surface of the ink receiving layer 31. In particular, this corresponds to an aspect in which the printing layer 11 is provided.

<Examples b3 to b6 (in-mold labels)>
In Example b1 of the in-mold label described above, Example 1 was performed in the same manner as Example b1, except that printing was performed on each of the stacked structures of Manufacturing Examples b2 to b5 instead of the stacked structure of Manufacturing Example b1. In-mold labels b3 to b6 were obtained. The layer configuration of the in-mold labels in Examples b3 to b6 corresponds to the same layer configuration as in Example b1.

<Comparative Example b1 (in-mold label / oxidized polymerization type ink use)>
In the above-described in-mold label example b1, instead of the toner composition B1 constituting the printing layer, a rosin-modified phenol resin (oxidation polymerization type) containing a coloring material as an ink composition B2 (T & K TOKA Co., Ltd.) Example b1 except that this ink composition B2 was printed using an offset printing machine (manufactured by Ryobi Co., Ltd., equipment name: RYOBI3300CR) using a product manufactured by Trade Name: BEST ONE Best SP). The in-mold label of Comparative Example b1 was obtained. As shown in FIG. 12, the layer structure of the in-mold label 202 of Comparative Example b1 has an ink printing layer 111 / ink receiving layer 31 / base material layer 21 containing a rosin-modified phenol resin containing a coloring material in this order. This corresponds to an aspect in which the ink print layer 111 is provided over the entire surface of the ink receiving layer 31. The in-mold label 202 of Comparative Example b1 forms the labeled container 201 by thermally fusing the ink print layer 111 to the wall surface of the resin molded body 2.

<Comparative Example b2 (in-mold label / photopolymerization type ink use)>
In Example b1 of the in-mold label described above, an acrylic ester oligomer (photopolymerization type) containing a color material (manufactured by T & K TOKA Co., Ltd.) was used as the ink composition B3 instead of the toner composition B1 constituting the printing layer. The product was manufactured in the same manner as in Example b1, except that the ink composition B3 was printed using an offset printing machine (manufactured by Ryobi Co., Ltd., device name: RYOBI3300CR). The in-mold label of Comparative Example b2 was obtained. As shown in FIG. 13, the layer structure of the in-mold label 204 of Comparative Example b2 has an ink printing layer 112 / ink receiving layer 31 / base material layer 21 containing an acrylic ester oligomer containing a coloring material in this order. This corresponds to an aspect in which the ink printing layer 112 is provided over the entire surface of the ink receiving layer 31. The in-mold label 204 of the comparative example b2 is to form the labeled container 203 by thermally fusing the ink print layer 112 to the wall surface of the resin molded body 2.

<Comparative Example b3 (in-mold label / printed surface is opposite)>
In Example b1 of the in-mold label described above, instead of printing the toner composition B1 on the ink receiving layer side of the laminated structure, the toner composition B1 is printed on the substrate layer side of the laminated structure. The in-mold label of Comparative Example b3 was obtained in the same manner as in Example b1. As shown in FIG. 14, the layer configuration of the in-mold label 206 of Comparative Example b3 corresponds to an aspect having the ink receiving layer 31 / the base material layer 21 / the printing layer 11 in this order. The in-mold label 206 of Comparative Example b3 forms the labeled container 205 by thermally fusing the ink receiving layer 31 to the wall surface of the resin molded body 2, and at this time, the printed layer 11 faces outward. Exposed.

<Comparative Example b4 (in-mold label / calcium carbonate-containing)>
In Example b1 of the in-mold label described above, except that printing was performed on the laminated structure of Production Example b6 instead of the laminated structure of Production Example b1, the same was performed as in Example b1, and A mold label was obtained. As shown in FIG. 15, the layer configuration of the in-mold label 208 of Comparative Example b4 has the printing layer 11 / ink receiving layer 31 / base material layer 121 containing calcium carbonate in this order. This corresponds to an aspect in which the printing layer 11 is provided throughout. The in-mold label 208 of Comparative Example b4 is to form the labeled container 207 by heat-sealing the printed layer 11 to the wall surface of the resin molded body 2.

[Manufacture of labeled molded products]
<Example b11 (molded article with label)>
Using a high-density polyethylene (manufactured by Nippon Polyethylene Co., Ltd., trade name: Novatec HD HJ490) as the molding resin C1, it was carried out on one side of a mold for molding a test piece of length 130 mm × width 150 mm × thickness 2 mm. The in-mold label (70 mm × 90 mm) of Example b1 was manually inserted and placed so that the base layer side was in contact with the mold, and this in-mold label was sucked and fixed to the mold. Next, the mold was clamped, and injection molding of the resin C1 melted at 230 ° C. was performed under an injection pressure of 750 kgf / cm ² by an injection molding machine (manufactured by Niigata Steel). After molding, the mold was cooled, the mold was opened, and the labeled test piece of Example b11 was obtained.
This test piece has a structure equivalent to that shown in FIG. About this test piece, the adhesive strength of the label, friction resistance, and visibility were evaluated. From the evaluation results using the test pieces, it can be seen that the in-mold label of the present invention can be suitably used for a labeled container.

<Examples b12 and b13 (molded products with labels)>
In Example b11 described above, the same procedure as in Example b11 was performed except that the resins C2 and C3 shown in Table 3 were used instead of the resin C1 constituting the resin molded body, and the same as shown in FIG. The labeled test pieces of Examples b12 and b13 having the following structure were obtained.

<Example b14 (molded article with label)>
In Example b11 described above, except that the in-mold label of Example b2 was used instead of the in-mold label of Example b1, the same procedure as in Example b11 was performed, and a structure equivalent to that shown in FIG. 11 was obtained. Then, a labeled test piece of Example b14 was obtained.

<Examples b15 and b16 (molded products with labels)>
In Example b14 described above, the procedure was the same as Example b14 except that the resins C2 and C3 shown in Table 3 were used in place of the resin C1 constituting the resin molded body, and the same as shown in FIG. The labeled test pieces of Examples b15 and b16 having the following structure were obtained.

<Examples b17 to b20 (molded products with labels)>
In the above-described Example b13, the same procedure as in Example b13 was performed except that the in-mold labels of Examples b2 to b5 were used instead of the in-mold label of Example b1, and the same as shown in FIG. The labeled test pieces of Examples b17 to b20 having a structure were obtained.

<Comparative Example b11 (molded product with label)>
In Example b13 described above, except that the in-mold label of Comparative Example b1 was used instead of the in-mold label of Example b1, it was performed in the same manner as Example b13 and had the same structure as shown in FIG. Thus, a labeled test piece of Comparative Example b11 was obtained.

<Comparative Example b12 (molded product with label)>
In Example b13 described above, except that the in-mold label of Comparative Example b2 was used instead of the in-mold label of Example b1, the same operation as Example b13 was performed and the structure equivalent to that shown in FIG. 13 was obtained. Thus, a labeled test piece of Comparative Example b12 was obtained.

<Comparative Example b13 (molded product with label)>
In Example b13 described above, instead of the in-mold label of Example b1, the in-mold label of Comparative Example b3 was manually inserted so that the printed layer side was in contact with the mold. Otherwise, the same procedure as in Example b13 was performed to obtain a labeled test piece of Comparative Example b13 having a structure equivalent to that shown in FIG.

<Comparative Example b14 (molded article with label)>
In Example b13 described above, except that the in-mold label of Comparative Example b4 was used instead of the in-mold label of Example b1, it was performed in the same manner as Example b13 and had the same structure as shown in FIG. Thus, a labeled test piece of Comparative Example b14 was obtained.

[Evaluation]
Table 4 shows a list of the structures of the molded products with labels and the evaluation results.

As is apparent from Table 4, the molded articles with labels of Examples b11 to b20 using the in-mold labels of Examples b1 to b6 provided with a printing layer containing a color material and an ethylene-based copolymer are resistant to friction. It is excellent in all of the properties, visibility, and adhesive strength, and it enables the protection and visibility of the printed content displayed on the side where the in-mold label and the resin molded body are in contact with each other. You can see that it is a combination. Furthermore, the results of Examples b14 to b16 show that good adhesiveness can be obtained even when the printing layer is partially provided.

On the other hand, the labeled molded products of Comparative Examples b11 and b12 using the in-mold labels of Comparative Examples b1 and b2 are obtained by heat-sealing the ink print layer to the wall surface of the resin molded body, but have sufficient adhesive strength. Was not obtained. Further, the molded product with the label of Comparative Example b13 using the in-mold label of Comparative Example b3 has poor wear resistance because the printed layer is arranged on the outer surface of the molded product with label and the printed content is exposed. Met. Moreover, since the base material layer contained a large amount of calcium carbonate, the labeled molded product of Comparative Example b14 using the in-mold label of Comparative Example b4 had poor transparency and poor visibility. .

DESCRIPTION OF SYMBOLS 1 Container with label 2 Resin molding 3 In-mold label 11 Print layer 21 Base material layer 31 Ink receiving layer 41 Laminated structure

Claims

An in-mold label provided on a resin molded body,
A substrate layer containing a thermoplastic resin, and a printing layer,
The printing layer contains a color material and an ethylene-based copolymer, and the printing layer can be heat-sealed to the wall surface of the resin molded body;
An in-mold label, wherein the substrate layer has an opacity of 40% or less.
The in-mold label according to claim 1, wherein the thermoplastic resin contains a polyolefin resin.
Between the base material layer and the printing layer, further having an ink receiving layer containing a polyethylene resin,
The in-mold label according to claim 1 or 2, wherein the opacity of the laminated structure having the base material layer and the ink receiving layer is 40% or less.
The in-mold label according to claim 3, wherein the polyethylene resin has a melting point of 135 ° C. or less.
The in-mold label according to claim 3 or 4, wherein the ink receiving layer has a thickness of 0.1 to 30 µm.
The in-mold label according to any one of claims 1 to 5, wherein the melting point of the ethylene copolymer is 135 ° C or lower.
The in-mold label according to any one of claims 1 to 6, wherein the ethylene copolymer includes an ethylene / methacrylic acid copolymer and / or an ethylene / vinyl acetate copolymer.
The in-mold label according to any one of claims 1 to 7, wherein the printed layer has a dot area ratio of 5 to 100%.
An in-mold molded body comprising a resin molded body and an in-mold label provided on the resin molded body,
The in-mold label is the in-mold label according to claims 1 to 8,
The in-mold molded product, wherein the printed layer is thermally fused to the wall surface of the resin molded product.
The in-mold molded product according to claim 9, wherein the resin molded product comprises a polyethylene-based resin.