WO2004049284A1

WO2004049284A1 - In-mold label having removable part

Info

Publication number: WO2004049284A1
Application number: PCT/JP2003/014902
Authority: WO
Inventors: Takashi Funato; Takatoshi Nishizawa; Masaki Shiina
Original assignee: Yupo Corporation
Priority date: 2002-11-22
Filing date: 2003-11-21
Publication date: 2004-06-10
Also published as: AU2003284630A1

Abstract

An in-mold label which comprises a thermoplastic resin base film layer and a heat-sealable resin layer, characterized in that the surface of the thermoplastic resin base film layer and/or the surface of the heat-sealable resin layer has an index of wetting of 34 to 73 mN/m, that the label is constituted of a label main part and a removable part and has perforations between the label main part and the removable part so that the removable part can be separated from the main part, and that when the label is adhered to a thermoplastic resin container in in-mold molding, the strength of adhesion between the removable part and the container is 80 to 270 gf/10 mm. This in-mold label has features that both sides thereof are printable, the removable part does not peel off the container during transportation or use, and the removable part, when desired to be removed, can be easily stripped off the container without being damaged.

Description

Specification

In-mold label with separation part

Technical field

TECHNICAL FIELD The present invention relates to an in-mold label having a cut-off portion, which is attached to a thermoplastic resin container manufactured by difference molding and hollow molding simultaneously with container molding. Background art

After setting the label in the mold in advance, the thermoplastic resin is injected into the mold, and the container is molded by injection molding, hollow molding, differential pressure molding, foam molding, etc., and the label is attached to the container at the same time. Some labels are known as labels used in the in-mold molding method (Japanese Patent Application Laid-Open No. 58-69015). No.).

As an example of such a label, a label with a separating portion such as a coupon has been proposed (Japanese Patent Application Laid-Open Nos. Hei 6-51701, Hei 6-95959, Kaihei 6—3 0 8 8 8 6 Reference). Labels with cut-outs may be provided with a perforation around the cut-out, so that the purchaser can easily peel off the cut-off after purchase, Adjust the amount of adhesive applied on the back side of the cut-off portion (see US Pat. No. 5,172,936), or do not apply adhesive only to that portion. What has been proposed.

However, such a label having a cut-off portion may be squeezed by the impact given during transportation after filling the contents into the resin container to which it is attached, or during the display of the product, or by squeezing the resin container. The load applied to the container during use has the disadvantage that the cut-off portion is more likely to rise than the container. On the other hand, if the amount of the adhesive at the cut-off portion is too large to prevent the floating, the cut-off portion may be detached from the perforation when the cut-off portion is peeled, despite the perforation being provided. There were problems such as tears in the detached part, making it difficult to remove the detached part cleanly. Also, when the separation part is used as a coupon, etc., if the separation part is only on the surface, There is also a demand for printing on the back side to be adhered to the container. When surface activation treatment or the like is performed so that the back side has sufficient adhesiveness to the printing ink, or when printing ink is printed, the adhesive strength between the cut-off portion and the container is reversed. There was a problem that it dropped significantly and the cut-off part was easily lifted up from the container. Disclosure of the invention

The inventors of the present invention have made it possible to perform double-sided printing, so that the cut-off portion does not float up from the container during transportation and use, and is easy to peel off when the cut-off portion is peeled from the container. The purpose of this study was to provide an in-mold label that would not be damaged.As a result of the study, we set the wetting index of the label surface to be printed and the adhesion strength between the cut-off part and the resin container within a specific range. That is, the present invention is directed to an in-mold label comprising a thermoplastic resin film base layer and a heat-sealable resin layer. Alternatively, the wetting index of the heat-sealable resin layer surface is 34 to 73 mN / m, and the label comprises a label body and a cut-off portion, and can be separated between the label body and the cut-off portion. As perforated When the label has a bond strength of 80 to 27 gf / 1 O mm between the cut-off portion and the container when the label is attached to the container during the in-mold molding of the thermoplastic resin container. Another object of the present invention is to provide an in-mold label characterized by the following.

In the in-mold label of the present invention, it is preferable that the peeling portion has a peeling start portion, and a release agent is applied to 55 to 80% of the surface of the heat-sealable resin layer at the separating portion. Further, it is preferable that the length of the slit portion constituting the perforation is 4 to 10 mm, and the interval between adjacent slit portions is 0.3 to 0.6 mm. Further, it is preferable that the surface of the thermoplastic resin film substrate layer and / or the surface of the heat-sealable resin layer of the in-mold label of the present invention is subjected to an activation treatment, and an antistatic layer is provided. Is preferably applied. The present invention also provides a container to which the label for in-mold is attached.

In the in-mold label of the present invention, the adhesive strength range between the cutoff portion and the container is adjusted to 80 to 270 gf / 1 O mm, and the container to which such a label is adhered is 10 times. Even after squeezing, the detached part has good appearance without lifting, and the detached part can be easily peeled off by hand. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a view showing the structure of an in-mold label of the present invention. In the figure, 1 is a label for in-mold, 2 is a separation part, 3 is a label body, 4 is a peeling start part, and 5 is a container.

FIG. 2 is a view showing a container to which the label manufactured in Example 1 is attached. Embodiment of the Invention

Hereinafter, the in-mold label of the present invention will be described in detail. In this specification, the numerical range represented by using “to” means a range including the numerical values described before and after “to” as the lower limit and the upper limit.

The in-mold label having a cut-off portion of the present invention is basically composed of a thermoplastic resin film base layer, and a heat-sealing resin layer formed on a side of the base layer to be adhered to the container. I have. Various types of information including coupons are printed on the surface of the base material layer, and a part of the label is provided with a cutout section separated by a perforation so as to be separated from the label body. In addition, a release agent (adhesive force reducing agent) is applied to the surface of the heat-sealable resin layer of the cut-off portion so that the cut-off portion can be easily peeled off, so that the adhesive strength is adjusted to an appropriate range. Furthermore, at least one end of the cutoff portion may be provided with a peeling start portion in which the amount of the release agent is adjusted more than other portions of the cutout portion.

FIG. 1 shows a specific embodiment of the in-mold label of the present invention. In the figure, 2 indicates a cut-off portion, 3 indicates a label body, and 4 indicates a peeling start portion. Peeling start part 4 with finger By detaching the cutout 4 from the container by pinching and pulling in the direction of the arrow b, the cutout 4 can be completely separated from the container body 3 by cutting along the perforations. . The details of the structure of the separation section 2 and the label body 3 and the shape of the peeling start section 4 are not particularly limited, and various modes as illustrated in (1) to (4) of FIG. It is possible.

Examples of the material constituting the thermoplastic resin film base layer include propylene-based resins, polyethylene resins such as high-density polyethylene and medium-density polyethylene, and polyolefin-based polymers such as polymethyl-11-pentene and ethylene-cyclic olefin copolymer. Resin, polyethylene terephthalate resin, polyvinyl chloride resin, polyamide resin such as nylon-16, nylon-6,6, nylon-16,10, nylon-16,12, etc., ABS resin, ionomer resin, etc. Films and the like can be mentioned. These resins may be used alone or as a mixture of two or more.

Of these, thermoplastic resins having a melting point in the range of 130 to 280 ° C., such as propylene-based resin, high-density polyethylene, and polyethylene terephthalate resin, are preferred. Further, those having a melting point higher by at least 15 ° C than the melting point of the thermoplastic resin constituting the heat-sealing resin layer described later are preferable. Among resins satisfying such conditions, propylene resins are particularly preferred in terms of chemical resistance, cost, and the like. Examples of such a propylene-based resin include a propylene homopolymer exhibiting isotactic or syndiotactic stereoregularity, and propylene, ethylene, 1-butene, 1-hexene, 1-heptene, and 4-methyl-1-methylbenzene. Copolymers with α-olefin such as 1-pentene can be exemplified. These copolymers may be binary, ternary or quaternary, and may be random copolymers or block copolymers.

In addition, inorganic fine powder or organic fine powder can be appropriately blended with the above-mentioned thermoplastic resin.

The type of the inorganic fine powder or the organic fine powder is not particularly limited. Of inorganic fine powder Examples include heavy calcium carbonate, light calcium carbonate, calcined clay, talc, barium sulfate, diatomaceous earth, magnesium oxide, zinc oxide, titanium oxide, silicon oxide, and the like. Among them, heavy calcium carbonate, calcined clay, and talc are preferable because they are inexpensive and have good formability.

As the organic fine powder, for the purpose of forming pores, select and use a resin that has a higher melting point or glass transition point than the thermoplastic resin used for the base material layer and is incompatible with each other. Is preferred. Specific examples include polymers or copolymers of polyethylene terephthalate, polybutylene terephthalate, polyamide, polycarbonate, polyethylene naphthalate, polystyrene, acrylate or methacrylate, melamine resin, polyethylene sulphite, and polyimidate. And polyphenylene sulfide, homopolymers of cyclic olefins, and copolymers (COC) of cyclic olefins with ethylene and the like. In particular, when a polyolefin resin is used as the above-mentioned thermoplastic resin, a homopolymer of a polyethylene terephthalate, a polybutylene terephthalate, a polyamide, a polycarbonate, a polyethylene naphthalate, a polystyrene, and a cyclic olefin may be used. It is preferable to select and use a copolymer (COC) such as ethylene. One of the above fine powders may be used alone, or two or more may be selected and used in combination. When two or more kinds are used in combination, an inorganic fine powder and an organic fine powder may be mixed and used.

Further, if necessary, a dispersant, an antioxidant, a compatibilizer, an ultraviolet stabilizer, an anti-opening agent and the like can be added.

The thermoplastic resin film base layer may be a single layer or multiple layers. In the case of a multi-layer structure, a core layer and a front layer and a back layer are disposed on both sides of the core layer. May be. When inorganic or organic fine powders are blended with these, the types and blending amounts thereof may be the same or different. The film constituting the thermoplastic resin film base layer is preferably stretched in at least one direction. When the thermoplastic resin film base layer is composed of a plurality of layers, at least one of the layers is preferably stretched. When a plurality of layers are stretched, they may be stretched individually before laminating each layer, or may be stretched after laminating. In addition, the stretched layer may be stretched again after lamination. Further, after forming the heat-sealing resin layer on the thermoplastic resin film base layer, the whole may be stretched.

Various known methods can be used for stretching, but it is preferable to perform stretching between rolls using a difference in peripheral speed between roll groups. According to this method, the stretching ratio can be arbitrarily adjusted. Also, since the resin is oriented in the flow direction of the film, it is possible to obtain a label having a high tensile strength and a small dimensional change due to the tension at the time of printing as compared with an unstretched film. The stretching temperature should be set above the glass transition point of the thermoplastic resin used for non-crystalline resins, and above the glass transition point of non-crystal parts to the melting point of crystal parts for crystalline resins. Can be. Preferable examples of the thermoplastic resin film substrate layer of the present invention include a film obtained by blending the above-mentioned thermoplastic resin with 8 to 80% by weight of an inorganic or organic fine powder, and further stretched in a uniaxial or biaxial direction. In addition, a film coated with a latex containing an inorganic filler on the surface, a film formed by vapor deposition or bonding of aluminum, and the like can be given.

Among them, biaxial resin compositions containing 5 to 30% by weight of inorganic fine powder, 3 to 20% by weight of high-density polyethylene and 92 to 50% by weight of propylene-based resin. a stretched film as a core layer, on both side surfaces, the inorganic fine powder 3 5-6 5 weight ^_0/0, high density polyethylene 0-1 0% by weight and the propylene-based resins of 5 5-3 5 wt% The use of a microporous stretched resin film, in which a uniaxially stretched film of a resin thread and a uniaxially stretched film is disposed as a front layer and a back layer, as a thermoplastic resin film base layer, such as printability and thermal shrinkage prevention, can be achieved. It is preferable from the viewpoint. The thickness of the thermoplastic resin film base layer is preferably 20 to 500 μπι. And more preferably 30 to 200 μπι. If the thickness is less than 20 jum, the supply of the label to the mold by the automatic label supply device tends not to be fixed at the proper position, or the label tends to be shirred. On the other hand, if it exceeds 500 μιη, the strength at the boundary between the resin molded product and the label formed by the in-mold molding is reduced, and the drop resistance of the resin molded product tends to be inferior.

The type of the resin constituting the heat-sealing resin layer is not particularly limited as long as it has a function of attaching to the resin material constituting the container to which the label is attached by heating during the in-mold molding. Examples of preferred resins, density 0.9 00 to 0.935 Low Density to medium density high-pressure polyethylene of gZ cm ^3, density 0. 880~0. 940 g / cm ³ straight chain linear polyethylene, Ethylene 'vinyl acetate copolymer, ethylene' ataryl acid copolymer, ethylene 'allylic acid alkyl ester copolymer, ethylene.methacrylic acid alkyl ester copolymer (alkyl group has 1 to 8 carbon atoms), ethylene ♦ Polyethylene resins having a melting point of 80 to 130 ° C such as metal salts of methacrylic acid copolymer (Zn, Al, Li, K, Na, etc.) can be mentioned.

Among these, high-pressure polyethylene or linear linear polyethylene having the above density, a crystallinity (X-ray method) of 10 to 60%, and a number average molecular weight of 10,000 to 40,000 is preferable. Above all the adhesion to the resin molded product, ethylene from 40 to 98 weight ^_0/0 and the α- Orefuin 60-2 wt% of carbon number 3-30, meta port Sen catalyst (especially meth port Sen alumoxane catalyst or, For example, using a catalyst comprising a meta-mouth compound as disclosed in International Publication WO 92/01723 and a compound which reacts with the metal-acene compound to form a stable anion. The linear linear polyethylene obtained by polymerization is most suitable. One of these polyolefin-based resins may be used alone, or two or more may be used in combination.

Other known resin additives can be arbitrarily added to the heat-sealable resin layer as long as the performance required for the heat-sealable resin layer is not impaired. That Examples of such additives include dyes, nucleating agents, plasticizers, mold release agents, antioxidants, antiblocking agents, flame retardants, and ultraviolet absorbers.

The heat-sealable resin layer may be formed by laminating the heat-sealable resin as a film on a base material layer to form a heat-sealable resin layer. There is a method of forming a heat-sealing resin layer by applying a resin solution dissolved in a solvent such as a mouth soap to a base layer and then drying it.

The thickness of the heat-sealing resin layer is preferably from 1 to 100 μm, more preferably from 2 to 20 μπι. The heat-sealable resin layer needs to be melted by the heat of molten polyethylene or propylene-based resin, which can be used as a parison during molding, to fuse the resin molded product and the label. The thickness of the resin layer is preferably at least 1 μπι. On the other hand, if it exceeds Ι Ο Ο, the label will curl, making offset printing difficult, and fixing the label to the mold tends to be difficult.

In order to improve printability, the thermoplastic resin film base layer and the heat-sealable resin layer have a wetting index of 34 to 7 SmNZnu, preferably 38 to 7 OmNZm, on the surface. . If the wetting index is less than 34 mNZm, the adhesion of the printed ink is poor and the ink tends to fall off. If it exceeds 73 mN / m, the front and back of the wound film tend to cause blocking. In addition, the wetting index in the present specification is a value measured according to JISK-6678.

The surface of the thermoplastic resin film substrate layer and / or the surface of the heat-sealable resin layer are activated by a known activation treatment such as edge discharge or flame plasma, and if necessary, an antistatic layer described later. The printability can be improved by adjusting the null index.

The thermoplastic resin film base layer and / or the heat-sealable resin layer may be provided with an antistatic layer after the activation treatment described above. Providing an antistatic layer As a result, the paper feeding and discharging properties on the printing press are improved, and troubles such as inserting two sheets in the paper feed unit during offset printing and deteriorating the paper alignment in some parts of the delivery can be prevented. In the present invention, the antistatic layer contains, for example, the following component (a) having antistatic properties alone, or a mixture of the following components (b) and (c) having ink adhesion properties. The solution can be formed by coating and drying.

(a) Ingredient:

Tertiary or quaternary nitrogen-containing acrylic polymer 100 parts by weight (b) Component:

Polyimine compound 0 to 300 parts by weight (c) Ingredient:

Epiclorhydrin adduct of polyamine polyamide 0 to 300 parts by weight The tertiary or quaternary nitrogen-containing acrylic polymer as the component (a) is composed of the following monomers (i) and (ii) And (iii) can be obtained by copolymerization.

(i) Ingredient:

From the compounds represented by the following general formulas (I) to (VII)

At least one monomer selected 4 to 94% by weight

(ii) Ingredients:

(Meth) acrylate 6 to 80% by weight (iii) Component:

Other hydrophobic vinyl monomer 0 to 20% by weight

General formula (I):

R ¹

General formula (Π):

R ¹

General formula (III):

General formula (IV)

General formula (V):

General formula

In the above formulas (I) to (VII), R ¹ represents a hydrogen atom or a methyl group, and R ² and R ³ each represent a lower alkyl group (preferably having 1 to 4 carbon atoms, particularly preferably having 1 to 4 carbon atoms). the ~ 2), R ⁴ is a saturated or unsaturated alkyl group or a cycloalkyl group having 1-2 2 carbon atoms, X- is quaternized N + pair Anion (e.g. halides, especially chloride), M represents an alkali metal ion (for example, sodium or potassium), and A represents an alkylene group having 2 to 6 carbon atoms. Among these monomers, it is preferable to use the compound of the general formula (VI) as the component (i).

(ii) The component (meth) acrylate is represented by the following general formula (VIII). General formula (VIII)

R ¹

H ₂ C = C—COOR ^{5 In the} formula, R ¹ represents a hydrogen atom or a methyl group, and R ⁵ represents an alkyl group, alkylene group or cycloalkyl group having 1 to 24 carbon atoms. Specific examples include butyl acrylate, force prill acrylate, stearyl methacrylate, and the like.

Specific examples of the other hydrophobic vinyl monomer which is the component (iii) include styrene and chloride butyl.

Among the tertiary nitrogen or quaternary nitrogen-containing acrylic polymers of the component (a), the water-soluble polymer having particularly preferable antistatic properties includes a monomer of the component (i) represented by the general formula (VI) In the monomers represented by, X— is C 1 _, which is “Saftoma ST-1100” or “Saftoma ST 110” from Mitsubishi Chemical Corporation. "," Saftoma ST-1330 ", and" Saftma ST-3200 ".

The polyimine-based compound as the component (b) is a primer for enhancing the adhesive force. For example, a polyethylenimine having a degree of polymerization of 200 to 3,000 represented by the following general formula (II), Ethyleneimine adducts of polyaminepolyamides, or alkyls using these as modifiers, such as alkyl halides having 1 to 24 carbon atoms, such as alkyl halides, alkenyl halides, cycloalkyl halides or benzyl halides Polyimine compounds selected from the group consisting of denatured, alkenyl-modified, benzyl-modified and aliphatic cyclic hydrocarbon-modified substances, and poly (ethyleneimine-urea). These are described in detail in Japanese Patent Publication No. 2-29010 and Japanese Patent Application Laid-Open No. H11-141736. General formula (IX):

In the formula, Z represents a group represented by one NH—R ⁹ or a polyamine / polyamide residue, and R ^{6 to} R ⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 24 carbon atoms. Or an alkenyl group, a cycloalkyl group or a benzyl group, at least one of which represents a group other than hydrogen, m is 0 to 300, and n, p and q are each independently 1 to 300 Indicates a numerical value.

The above-mentioned component (c), a polyamine polyamide 'epichlorhydrin adduct, is also a primer for enhancing the adhesive strength. Such a primer is, for example, a polyamide comprising a saturated dibasic carboxylic acid having 3 to 10 carbon atoms and a polyalkylene polyamine. Water-soluble and cationic thermosetting resins obtained by reacting phenol with epichlorohydrin. Such a thermosetting resin is described in detail in Japanese Patent Publication No. 35-34747. Specific examples of the saturated dibasic carboxylic acid having 3 to 10 carbon atoms include dicarboxylic acids having 4 to 8 carbon atoms, particularly adipic acid. Further, specific examples of the polyalkylene polyamine include polyethylene polyamine, particularly ethylene diamine, diethylene triamine, and triethylene tetramine, and particularly, diethylene triamine.

In addition to these components, for example, sodium carbonate, sodium sulfate, sodium sulfite, sodium thiosulfate, barium hydroxide, sodium metasilicate, sodium pyrophosphate, sodium tripolyphosphate, sodium first phosphate, potassium alum, ammonia light Water-soluble inorganic compounds such as alum, water-soluble organic solvents such as ethyl alcohol and isopropyl alcohol, surfactants, water-soluble polymerization agents such as ethylene glycol and polyvinyl alcohol, and other auxiliary materials as required You can mix it. These components (a), (b) and (c) are used as an aqueous solution having a total solid content of generally 0.1 to 10% by weight, preferably 0.1 to 5% by weight. The amount of coating, on one basis with solid content on drying 0. 005~ ² g / m 2, preferably provided in a range of 0. 02~1 g / m ^2. As a method for applying the above composition, for example, a normal application method such as a die, a bar, a launale, a blade, an air knife, a size press, a spray coat, and a combination thereof can be adopted. By drying this at normal temperature to 100 ° C., an antistatic layer having a thickness of 0.005 to 2 μπι can be obtained.

The mixing ratio of the components (a), (b) and (c) is such that the polyimine compound of (b) is 0 to 300 parts by weight, preferably 100 parts by weight of the nitrogen-containing acryl resin of (a). 0 to 200 parts by weight, and the epichlorohydrin adduct of the polyamine polyamide (c) is 0 to 300 parts by weight, preferably 0 to 200 parts by weight. By maintaining these compositions, the surface of the thermoplastic resin film base layer and / or the surface of the heat-sealable resin layer are less likely to be charged with static electricity, and the paper feeding / discharging property is improved. The surface resistivity measured by JIS K-6911 of each of the thermoplastic resin film base layer and the Z or heat sealing resin layer is preferably in the 9 to 15 power range, more preferably in the 9 to 12 power range. is there.

On the surface of the thermoplastic resin film base layer and the surface of the heat-sealing resin layer of the present invention, various information such as a product name, a character, a percode, a manufacturer, a sales company name, a use method, a coupon, and a lottery are printed. can do. As a printing method, for example, various printings such as gravure printing, offset printing, letter press printing, flexo printing, and screen printing can be performed. As described later, printing on the heat-sealable resin layer side can use the printing ink varnish itself as a release agent. Further, the surface of the thermoplastic resin film base layer can be deposited with metal such as aluminum or hot stamped, and an overcoat layer such as lamination or varnishing can be formed.

Also, at least one end of the cut-off portion is 3 to 10 mm, preferably 5 to 8 mm The peeling start portion may be formed with a width of (a) in FIG. If the width of the peeling start portion is less than 3 mm, it is difficult to make a trigger for peeling and it is difficult to grasp by hand.If the width exceeds 1 Omm, the peeling start portion is turned up after in-mold molding. And the container looks worse. Furthermore, if a notch is formed at the end of the boundary between the separation start portion and the container, the separation portion can be more easily peeled off.

The in-mold label of the present invention is capable of preventing the detached portion from rising even when a shock or load is applied to the container at the time of filling, transporting, displaying product shelves, and during normal use of the resin container to which the label is attached. In addition, the adhesive strength between the cut portion and the resin container is in a specific range, such that the cut portion can be peeled off, that is, 80 to 270 gf / 1 Omm, preferably 100 to 250 gf Zl 0 mm. It is characterized in that it is preferably adjusted to the range of 120 to 240 gf / 1 Omm. If the adhesive strength is less than 80 gf Zl 0 mm, the floating of the cut-off portion tends to be a problem. Conversely, if the adhesive strength is greater than 270 gf / 1 Omm, it will be difficult to peel off the cut off part from the container.

The adhesive strength is adjusted by applying a release agent to the surface of the heat-sealable resin layer at the separation portion. As a specific method for keeping the adhesive strength in the above range, it is preferable to provide a release agent for 55 to 80% of the area of the adhesive between the cutoff portion and the container, and to provide a release agent for 60 to 75%. Is more preferred. If the area of the release agent is out of the range of 55 to 80%, it tends to be difficult to maintain the adhesive strength between the cut-off portion and the resin container in the above specific range. The amount of the release agent to be applied to the above-mentioned peeling start part is preferably more than 80% and up to 95%, more preferably more than 80% and up to 90% of the area of the peeling start part.

Various printing inks and varnishes can be used as the release agent. Examples of inks include any of the following: offset ink, UV offset ink, gravure ink, silk screen ink, flexo ink, UV flexo ink, and the like. Further, for example, a release varnish containing silicon, a release varnish containing a fluorinated compound, a wax, or the like can be used. Special method for applying release agent Although there is no limitation, it is generally performed by letterpress printing, offset printing, gravure printing, flexographic printing, screen printing, or the like.

The degree of lifting of the cut-off portion was determined by a test in which a resin container with a label attached was squeezed. In the present invention, the squeeze test is performed by a container deformation test method described later, assuming that a resin container to which a label is attached is usually used.

One-sided or two-sided imprint labels are separated into labels of the shape and dimensions necessary for attaching resin containers by punching, but during or before this punching It is preferable to provide perforations around the cut portion (excluding the peeling start portion) to facilitate the peeling of the cut portion. For the perforation, a hot needle, an electron beam, a laser beam, or the like is used, and the length of the slit portion is 4 to 10 mm, preferably 5 to 8 mm, and the interval between adjacent slit portions is 0.3 to 0.3 mm. It is formed so as to have a thickness of 6 mm, preferably 0.3 to 0.5 mm. The length of the slit portion in the present specification means the length of the through hole forming the slit in the longitudinal direction. If the length of the perforated slit is too short, or if the interval between adjacent slits is too long, it is difficult to peel off the perforated shape, and conversely, the length of the perforated slit If the label is too long or the distance between adjacent slits is too short, problems such as breakage or breakage may easily occur when handling the label.

If the perforations are formed from the heat-sealable resin layer side of the in-mold label toward the printing surface, the slit wall on the heat-sealable resin layer side is formed smoothly, and the perforations are formed during in-mold molding. The outer wall portion of the slit does not cut into the outer wall of the container, and the separation portion can be more easily peeled off.

The in-mold label of the present invention includes a base material layer for an in-mold label in a mold cavity such as a differential pressure molding such as vacuum molding or air pressure molding, or a hollow molding in which a parison is pressure-bonded to the inner wall of a mold by air pressure. After the printing side is set in contact with the mold wall, it is fixed to the mold inner wall by suction of the mold. Next, the molten resin or parison of the resin film of the container molding material is guided into a mold, and molded by a conventional method. A container is formed in which the label is fused integrally to the container outer wall.

In the labeled container obtained in this way, the label and the resin container are molded integrally after the label is fixed in the mold, so there is no unexpected deformation of the label and the container itself and the label are in close contact with each other. The strength is strong, there are no blisters, and the container decorated with labels has a good appearance. However, if the separation starts from the separation start part of the separation part, and the end of the separation part is picked with a finger and pulled by hand, the separation part is peeled off according to the perforation, and the separation part is easily formed. Can be.

The type of thermoplastic resin material used for the container to which the label is attached is not particularly limited. Preferred examples include thermoplastic resins such as propylene-based resin, polyethylene (preferably high-density polyethylene), polychlorinated vinyl, polyethylene terephthalate, and polyamide, which are the same as those used for the label for the in-mold. it can. The type of these thermoplastic resins can be appropriately selected according to the purpose of use, use environment, and use mode of the molded article after in-mold molding.

Hereinafter, features of the present invention will be described more specifically with reference to examples and comparative examples. Materials, used amounts, ratios, treatment details, treatment procedures, and the like shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples described below.

(Example 1)

The preparation of the catalyst was carried out according to the preparation method disclosed in Japanese Patent Application Laid-Open (JP-A) No. 61-130314. That is, to a complex of ethylene-bis (4,5,6,7-tetrahydroindenyl) zirconium dichloride (2.0 mmol), methylalumoxane (manufactured by Toyo Stoffer Co., Ltd.) was added at a molar ratio of 1,000 to the above complex. Then, a catalyst solution was prepared by diluting with toluene to 10 liters, and polymerization was carried out by the following method. A mixture of ethylene and 11-hexene was supplied to a 1.5-liter continuous stirring type autoclave continuous reactor so that the composition of 1-hexene was 80% by weight. The reaction was carried out at 160 ° C. while maintaining the internal pressure at 1,600 kg / cm ² .

After the reaction is completed, the MFR is 18 g / 10 min, the density is 0.898 g / cm ³ , and the Q value is

1.9. The TREF elution curve has one peak, the peak temperature of which is 50 ° C, and the HZW at the peak temperature is 1.5 ethylene-olefin copolymer (1 xylene content 22% by weight). Obtained. The integrated elution volume is 2.1% at 10 ° C and 20%

3.0% and 100% at 80 ° C.

It was produced by an autoclave method at a reaction temperature of 260 ° C and a reaction pressure of 1,500 kg / cm ² . A high-pressure low-density polyethylene having an MFR of 4 g / 10 min, a density of 0.92 gZcm ³ , an ME of 2.4 and a Q value of 10 was obtained.

Polypropylene homopolymer (trade name “Novatech PP MA-8”, melting point 164 ° C, manufactured by Nippon Polychem Co., Ltd.) 67% by weight, high-density polyethylene (trade name “Novatech HD HJ580”, melting point 134 ° C , Nippon Polychem Co., Ltd.) 10 weight ^_0/0 and an average particle size of 1. 5 μπι consisting of calcium carbonate powder 23% by weight of the resin composition (Alpha), was kneaded at 250 ° C using an extruder After that, the film was extruded from a die and cooled to a temperature of about 50 ° C. After the film was heated again to about 150 ° C, it was stretched four times in the machine direction using the peripheral speed of the roll group to obtain a uniaxially stretched film as a core.

—Propylene homopolymer (trade name “Novatech PP MA_3”, manufactured by Nippon Polychemical Co., Ltd.) 51.5% by weight, high-density polyethylene (brand name “Novatech HD HJ580”, manufactured by Nippon Polychem Co., Ltd.) 3.5) Weight ⁰ /. A resin composition (Β) consisting of 42% by weight of calcium carbonate powder having an average particle size of 1.5 μm and 3% by weight of titanium oxide powder having an average particle size of 0.8 μΐη was heated to 240 ° C using another extruder. This was extruded from a die into a film on the surface of the uniaxially stretched film and laminated (B / A) to obtain a laminate of a surface layer and a Z core layer.

Furthermore, using separate extruders, propylene homopolymer (trade name “Nova Tech PP MA- 3 ", Japan Polychem, Ltd. Co., Ltd.) 51.5 weight ^_0/0, high density poly ethylene (trade name" Novatec HD HJ 580 ", Japan Polychem Co., Ltd.) 3.5% by weight, average particle size 1. 5 mu 42 wt% calcium carbonate powder of m and the average particle diameter 0. 8 zm titanium oxide powder 3 wt ^_0/0 from a composition of (C), and Hitoshi one

c

(D) a resin composition comprising 75% by weight of the above-mentioned ethylene / α-olefin (1-hexene) copolymer and 25% by weight of the high-pressure ecu method low-density polyethylene,

H o

Is melt-kneaded at 200 ° C, supplied to one co-extrusion die, laminated in the die, and extruded into a film form from the die.H3, heat-sealing resin is applied to the back side of the uniaxially stretched film. The layers were laminated (B / A / C / D) so as to be the outermost layers, to obtain a laminate having a four-layer structure of a front layer, a non-coat layer, a back layer, and a heat-sealable resin layer.

This four-layer film is guided to a tenter oven, heated to 155 ° C, stretched 7 times in the transverse direction using a tenter, then heat-set at 164 ° C, cooled to 55 and slit the ears. After that, corona discharge treatment was performed on both the front and back surfaces at a strength of 50 W / m ² Z. Thereafter, an aqueous solution of a composition containing the following (a), (b) and (c) was applied to the surface layer side and dried to form an antistatic layer.

(a) A quaternary nitrogen-containing acrylic terpolymer consisting of the following units:

0.5% by weight

40% by weight

4H ₉ 35% by weight

25% by weight (B) butylated modified polyethylene I Min 0.3 wt ^_0/0

(c) Epiclorhydrin adduct of water-soluble polyamine polyamide

(WS-570 (trade name), manufactured by PMC Japan, Ltd.) 0.5% by weight (d) Water Residual surface of thermoplastic resin film substrate layer (surface layer) and heat-sealable resin layer Was measured using an ACCU DYNE TESTJ made by Diversified Enterprises and found to be Y OmNZm 4 2mNZm, respectively. In addition, cross-sectional observation using an electron microscope revealed that the four layers excluding the antistatic layer were The thickness was 100 μχα (B / A / C / D = 30/40/25/5 μm), and the density of the entire laminated stretched resin film was 0.78 g / cm. ^{Was 3} .

The obtained laminated stretched resin film having a five-layer structure (the antistatic layer ZB / A / C / D) was cut into a chrysanthemum half size by a sheet cutter to obtain a sheet sheet for an in-mold label.

Printing>

On the front side of the sheet for in-mold labels obtained in this way, Komori Corporation's offset printing machine “Rithlon” and T & K TOKA's UV offset ink “Best Cure I” were used. At a speed of 6,000 sheets / 11, the product name, manufacturer, sales company name, character, barcode, usage method, etc. UV offset 4 color printing was performed, and the adhesion of each color ink was good. Was.

Further, the content of the coupon was printed using the UV offset ink on a portion corresponding to a cut-off portion on the surface of the heat-sealable resin layer on the back side of the sheet (label). After that, a release varnish containing silicon (trade name “Oil-based Hakuri OP Varnish”, manufactured by T & K TOKA) was printed using the same offset printing press. These inks and mist were printed so as to be 75% of the area of the cut-off portion. Further, at the peeling start portion, printing was performed so as to be 90% of the area using the varnish described above. These inks and The adhesion of the varnish was good.

Next, a sewing machine in which slits having a length of 6.0 mm were provided at intervals of 0.5 mm in the longitudinal direction around the cut-off portion of the printed sheet of the in-mold label excluding the peeling start portion. An eye was formed, and then the label portion was punched out into a label having a length of 11 cm and a width of 9 cm by punching to obtain an in-mold label having a cut-off portion. The details of the structure of the imprint label are as shown in FIG.

<Paste>

After fixing the label for the inner mold to one side of the split mold for blow molding using a vacuum so that the surface layer side is in contact with the mold, high-density polyethylene (trade name “Novatech HDHB330”, melting point 13) 4 ° (made by Nippon Polychem Co., Ltd.) is melt extruded at 220 to form a parison, the split mold is closed, 4.2 kg / cm ² of compressed air is supplied into the parison, and the parison is expanded. After the molding, the mold was cooled and the mold was opened to obtain a resin hollow container having a content of 100 m1. Fig. 2 shows a front view and a cross-sectional view of the obtained container with the label attached.

This hollow container did not fade in label printing, and did not show shrinkage of the label or generation of pristers. In addition, there was no lifting of the separation part from the container.

(Example 2)

In the same manner as in Example 1 except that the coating area was set to 60% of the area of the cut-off portion in the coating of the release agent, an in-mold label having a cut-off portion and a resin made of the label were attached. A container was obtained. In this hollow container, label printing did not fade, and no label shrinkage or blistering was observed. Also, there was no lifting of the cut-off part from the container.

(Example 3)

In Example 1, after coating on the surface layer side, an aqueous solution containing only 1.0% by weight of the above-mentioned quaternary nitrogen-containing acrylic terpolymer (a) was further coated on the back side, followed by drying. After drying, an antistatic layer was provided on both front and back surfaces. At this time, the wetting index of the surface of the heat-sealable resin layer on the back side was 5 OmN / m. Otherwise in the same manner as in Example 1, a resin container having an in-mold label and a label having a cut-off portion attached thereto was obtained. Also in this hollow container, there was no fading in label printing, and no shrinkage and blistering of the label were observed. In addition, there was no lifting of the separation part from the container.

(Comparative Example 1)

In applying the release agent, an in-mold label having a cut-off portion was applied in the same manner as in Example 1 except that the coating area was 90% of the area of the cut-off portion. A resin container was obtained.

(Comparative Example 2)

In applying the release agent, an in-mold label having a cut-off portion was applied in the same manner as in Example 1 except that the coating area was set to 50% of the area of the cut-off portion. A resin container was obtained.

(Comparative Example 3)

In accordance with the content of Example 1 described in JP-A-6-308886, a thin mold label having a cut-off portion and a resin container to which the label was attached were obtained.

(Comparative Example 4)

An in-mold label having a cut-off portion and a resin container to which the label was attached were obtained in the same manner as in Example 1 except that the corona discharge treatment was changed to 10 WZm ² / min. The wetting indices of the surfaces of the thermoplastic resin film base layer and the heat-sealing resin layer were 66 mNZm and 32 mN / m, respectively.

(Comparative Example 5)

An in-mold label having a cut-off portion and a resin container to which the label was attached were obtained in the same manner as in Example 1 except that the corona discharge treatment was not performed. The wetting indices of the surfaces of the thermoplastic resin film substrate layer and the heat-sealing resin layer were 31 m NZm and 30 ra NZm, respectively. (Comparative Example 6)

An in-mold label having a cut-off portion and a resin container to which the label was attached were obtained in the same manner as in Example 3, except that the corona discharge treatment was not performed on the heat seal layer side in Example 3. The wetting indices of the surfaces of the thermoplastic resin film base material layer and the heat sealing resin layer were 7 OmNZm and 32 mN / m, respectively.

(Test example)

The following method was carried out by using the sheet manufactured in each example and the comparative example, 100 sheets of an ink mold label having a cut-off portion, and 20 resin containers with the label. The performance was measured and evaluated. Table 1 shows the results.

(1) Inserter suitability

100 labels were continuously supplied to the blow mold split mold by the automatic label supply device (label insert robot "NR 75W", manufactured by Pentel Co., Ltd.) used when attaching labels to containers. . At this time, the following criteria were used to evaluate whether there were any troubles such as label breakage, label cut, and label falling off the mold. Table 1 shows the results.

〇: No trouble occurred.

X: The label was broken, cut, misaligned, or dropped.

(2) Measurement of adhesive strength

Cut off the label-attached part of the labeled container with a wrench knife, cut the separated part coated with release varnish into 1 Omm wide strips, and forcibly peel off one end of the container and the adhesive part by 1 Om m hand. , A tensile tester (trade name “Autograph AGS-5KND”, manufactured by Shimadzu Corp.), and fix the other end in the same way, then pull in 180 degrees in the peeling direction. A tensile test was performed at a speed of 30 Omm / min to measure the adhesive strength between the label and the container. Table 1 shows the results.

(3) Squeeze aptitude Prepare 20 containers each with an in-mold label with a cut-off section, and hold the sides of the containers so that the inner walls of the containers can be held together by human hands under the conditions that the internal pressure of the containers can escape freely. The squeeze test was performed by performing a pressure operation 5 to 10 times continuously in the facing direction. After each pressurizing operation, the presence or absence of label peeling was evaluated from the appearance evaluation. Table 1 shows the results.

The appearance evaluation in Examples and Comparative Examples was performed according to the following criteria.

〇: In all cases, there is no lifting of the label from the container.

Δ: Some of the peeling start portions were observed to be lifted, but there was no practical problem. X: Some of the cut-off parts are not lifted and have no commercial value.

(4) Peelability

Twenty containers each having an in-mold label having a cut-off portion were prepared, and a peel test was performed by a human hand on the cut-off portion, assuming that the cut-off portion was actually peeled off.

The ease of peeling and the ease of cutting at this time were evaluated according to the following criteria. Table 1 shows the results.

〇: All are easily peeled.

X: Impossible to peel (there is a case where the resin film substrate layer is broken and the cut-off part cannot be peeled cleanly).

〇: All cuts can be cut cleanly as perforated.

Δ: Some of the cuts were cracked during peeling and could not be cut cleanly.

X: Cannot be cut. (Some of the cut part is torn during peeling and cannot be cut.)

(5) Printability

Measurement of antistatic performance>

Each label is used as an antistatic property on the paper surface, which is a measure of stable printability. The surface specific resistance of the front and back surfaces was measured according to JISK-6911 using an insulation resistance meter DSM-8103 manufactured by Toa Denpa Kogyo KK.

Paper running performance>

Under the above printing conditions, observe the state of sheet feeding on the printing press during continuous printing, and the state of paper alignment in the printing press delivery section after drying with a UV irradiator. Evaluation was made according to the following criteria.

〇: The paper feeds and runs smoothly on the printing press, and the paper alignment in the delivery section is good.

X: Trouble that often occurs during paper feeding, paper alignment in the delivery section is bad.

The degree of adhesion of the ink after drying with a UV irradiator was evaluated according to the following criteria by observing the state when Nichipan “Cellotape (registered trademark)” was adhered and peeled off. .

〇: In some cases, the ink does not come off and the base layer may break down.

Δ: There is resistance when peeling, but most of the ink is peeled, and there is a practical problem.

X: The entire amount of the ink is peeled off, and there is almost no peeling resistance.

table 1

Lapel for in-mold In-mold suitability evaluation (label / bottle) Sheet applicability sheet printability evaluation

Stripping agent application area (%) Perforation cutting condition (mm) Squeezing suitability Peeling suitability

Item Wetting index Ink Specific surface resistance

Lapel / Portle

Inserter (mN / m) Adhesive paper passing Adhesive strength

S, J-section Slit section

(igf / 10mm) 5 times 10 times

Length spacing Deformability Ease of deformation

Base material surface Heat seal surface Heat seal surface Base material surface Heat seal surface Example 1 90 75 6 0.5 O 180 O ooo 70 42 o 2X10 "1X10 o Example 2 90 60 6 0.5 o 240 O ooo 70 42 o 2X10 "10 ¹⁵ o Example 3 90 75 6 0.5 o 130 oooo 70 50 o 2X10" 8X10 ^t0 o Reciprocal 1 90 90 60.5 o 50 m X oo 70 42 o 2X10 "1X10 ¹⁵ o Comparative example 2 90 50 6 0.5 o 360 oo m X 70 42 o 2X10 "1 X10 ¹⁵ o Comparative example 3 1 ― 0.7 0.7 o TOO o m o m 43 31 X 1 X10 ¹⁶ 1 10 ¹⁵ X Comparative example 4 90 75 6 0.5 o 190 oooo 66 32 Δ 7x10 "1 10 ¹⁵ o Comparative example 5 90 75 6 0.5 o 210 oooo 31 30 X Ιχ10 ^{ϊδ 1X10} X Comparative example 6 90 75 6 0.5 o 110 o m oo 70 32 X 2 10" 5X10 ¹² O

Claims

The scope of the claims

1 · An in-mold label consisting of a thermoplastic resin film base layer and a heat-sealable resin layer, wherein the surface of the thermoplastic resin film base layer and / or the surface of the heat-sealable resin layer has a wetting index of 34 to 73. mNZm, and the label is composed of a label body and a separation portion, and a perforation is provided between the label body and the separation portion so that the label can be separated, and the label is made of a thermoplastic resin container. An in-mold label, wherein the adhesive strength between the cut-off portion and the container when attached to the container during in-mold molding is 80 to 270 g fZl Omm.

2. The rabenole for immonored according to claim 1, wherein both the wetting index of the surface of the thermoplastic resin film base layer and the surface of the heat-sealing resin layer are 34 to 73 mN / m.

3. The label for in-mold molding according to claim 1, wherein a wetting index of the surface of the thermoplastic resin film base layer and the surface of the Z or heat sealable resin layer is 38 to 70 mN / m.

4. The thermoplastic resin film base layer is composed of a resin composition containing 5 to 30% by weight of an inorganic fine powder, 3 to 20% by weight of a high-density polyethylene, and 92 to 50% by weight of a propylene resin. A biaxially stretched film is used as the core layer, and on both sides thereof, 35 to 65% by weight of inorganic fine powder and 0 to 10% by weight of high-density polyethylene. / ₀ and propylene resin in any range first to third terms in accordance with the structure arranged an axially oriented film as a surface layer及Pi backside layer of the resin composition in a proportion of 55-35 wt% The label for the described in-mold.

5. The heat-sealing resin layer has a density of 0.900 to 0.935 g / cm ³ and a crystallinity (X-ray method) of 10 to 60. /. The high pressure method polyethylene having a number average molecular weight of 10,000 to 40,000, or a linear linear polyethylene having a density of 0.880 to 0.940 gZcm ³ . An in-mold label according to any of the above.

6. The thickness of the thermoplastic resin film base layer is 20 to 500 μπι, The in-mold label according to any one of claims 1 to 5, wherein the thickness of the heat-sealing resin layer is 1 to 100 / zm.

7. The rabenole for immonoredo according to any one of claims 1 to 6, wherein the surface of the thermoplastic resin film layer and / or the surface of the heat-sealable resin layer is activated.

8. The in-mold label according to claim 7, wherein the surface of the thermoplastic resin film base layer and the surface of the Z or heat sealable resin layer are subjected to a corona discharge treatment.

9. The surface of the thermoplastic resin film layer and / or the surface of the heat-sealable resin layer has been subjected to an activation treatment, and the surface having been subjected to the activation treatment is further provided with an antistatic layer. Item 9. The label for immonoreddo according to item 7 or 8.

10. The label according to claim 9, wherein the antistatic layer contains a tertiary or quaternary nitrogen-containing acrylic polymer.

11. The imprint label according to claim 9 or 10, wherein the antistatic layer contains a polyimine compound and / or an epichlorohydrin adduct of a polyamine polyamide.

12. In-mold having a cut-off portion according to any one of claims 1 to 11, wherein printing is performed on the surface of the thermoplastic resin film base layer and / or the surface of the heat-sealable resin layer. For labels.

13. The separation portion according to any one of claims 1 to 12, wherein a release agent is applied to 55 to 80% of the area of the heat sealing resin layer surface of the separation portion. Lavenore for innomoredo.

14. Claims 1 to 13 wherein the length of the slits constituting the perforations is 4 to 1 O mm, and the interval between adjacent slits is 0.3 to 0.6 mm. The label for imprint according to any one of the above.

1 5. The length of the slit that constitutes the perforation is 5 to 8 mm. 14. The imprint label according to any one of claims 1 to 13, wherein an interval between the slit portions is 0.3 to 0.5 mm.

1 6. The imprint label according to any one of claims 1 to 15, wherein the adhesive strength between the cutoff portion and the container is 120 to 240 g fZl Omm.

17. The label for immonoredo according to any one of claims 1 to 16, wherein the separation portion has a peeling start portion.

18. The in-mold label according to claim 17, wherein a release agent is applied to more than 80% and up to 95% of the area of the peeling start portion.

19. The in-mold label according to claim 17, wherein the width of the peeling start portion is 3 to 10 mm.

20. A container to which the in-mold label according to any one of claims 1 to 19 is attached.