JP2002258752A - Label for in-mold molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a label for in-mold molding which does not lower heat sealing property even when heated in printing, particularly UV offset printing in label production and even when stored over a long period of time particularly at high temperature in the summer, fusion-bonds tightly to a vessel, has good antistatic performance and is excellent in suitability to printing, cutting, blanking and insertion in a metallic mold throughout the year. SOLUTION: The label for in-mold molding is a multilayer film comprising a thermoplastic resin film substrate layer (I) and a heat sealing resin layer (II) and this resin layer (II) comprises a thermoplastic resin composition containing a permanent antistatic agent based on a polyether ester amide and a metallic salt (or ionomer) in a polyolefin resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parison made of a thermoplastic resin melted in a mold by setting the label in a mold in advance so that the printed side of the label is in contact with the mold wall. The present invention relates to a label used in in-mold molding for producing a label bonding container by hollow molding or injection molding a molten thermoplastic resin, or vacuum forming or pressure forming a molten thermoplastic resin sheet. is there.

[0002]

2. Description of the Related Art Conventionally, in order to integrally mold a resin-molded container with a label, a blank or a label is inserted in a mold in advance, and then the mold is formed by injection molding, hollow molding, differential pressure molding, foam molding or the like. A container is formed inside the container, and the container is painted or the like (see JP-A-58-69015 and European Patent Publication No. 254923). Such labels for in-mold molding include gravure-printed resin films, offset multicolor printed synthetic paper (for example, see Japanese Patent Publication No. 2-7814 and Japanese Patent Application Laid-Open No. 2-84319), or aluminum. Aluminum labels and the like are known in which a high-pressure low-density polyethylene and an ethylene / vinyl acetate copolymer are laminated on the back surface of a foil and the surface of the foil is gravure-printed.

However, in the method of manufacturing a label-laminated container decorated with a label by in-mold molding using the above-described label or blank for in-mold molding, an automatic label supply device is used to place the container in a mold. When supplying labels, if the antistatic function of the labels is insufficient,
Particularly in a low-humidity environment in winter, static electricity between stacked labels is not removed, and two or more labels are simultaneously supplied into a mold, and a container having an improperly attached label (an improperly attached container). Non-defective products) or the labels are dropped off and cannot be used effectively. In addition, during the label manufacturing process, printing and printing on films and synthetic paper, especially during offset printing, the supply and discharge of these films deteriorates, and the problem that the label manufacturing machine must be stopped and restarted many times is pointed out. Have been.

In order to solve such a problem, a transferable low molecular weight antistatic agent such as sorbitan monooleate and glycerin monostearate is kneaded into an ethylene resin which is a heat-sealable resin layer of a label. In-mold molding labels and in-mold molding labels with an antistatic film formed by applying and drying a low molecular weight antistatic agent such as a polyoxyethylene derivative on the surface of the heat-sealable ethylene resin layer Proposed.

[0005] However, both of the in-mold molding labels have the drawback that the long-term durability of the antistatic function is short. In addition, in the former in-mold molding label, the antistatic function kneaded into the heat-sealable resin layer is used. The transfer of the agent component to the surface significantly impairs the heat-sealing resin's ability to fuse to the container, and a defective container in which the label does not fuse to the container is formed or adhered to the container. There was a problem of forming a defective product in which blisters occurred on the label. In order to solve the above problems, a method has been proposed to solve the above problems by including a polyetheresteramide having a long-lasting and specific tacky antistatic function in a heat-sealing resin. (See JP-A-11-352888).

[0006]

However, when a polyetheresteramide is kneaded with a heat-sealable resin using a low-molecular-weight modified polyethylene as a compatibilizer to form a label for in-mold molding, a step of printing the label is used. If the label is left at 60 ° C. for several days or at 40 ° C. for several months during the storage period until the in-mold molding, the original heat sealability of the label is significantly reduced, and It has been found that blisters are generated when molded, and that the label is easily peeled off due to reduced adhesion strength. The present invention provides heating during label processing during label production, particularly UV offset printing, and a storage period, particularly when stored for a long period of time at high temperatures in the summer. Good antistatic properties, printing throughout the year,
An object of the present invention is to provide a label for in-mold molding which is excellent in cutting, punching, and insertability into a mold.

[0007]

As a result of intensive studies to solve these problems, the present inventors have found that a polyolefin resin which is a heat-sealing resin layer contains a polyolefin resin containing a metal salt or an ionomer. By containing ether ester amide, heat sealability does not decrease even if it is kept at high temperature for a long time during label printing and storage, and the paper supply / discharge property during label printing and paper alignment when cutting The present invention has been found to be able to achieve the intended purpose effectively by reducing the insertion error of the label into the mold at the time of in-mold molding, and to provide the present invention.

That is, the invention of the present application is a multilayer film comprising a thermoplastic resin film base layer (I) and a heat sealing resin layer (II), wherein the heat sealing resin layer (II) is a polyolefin resin. (A) a thermoplastic resin composition containing a polyetheresteramide (b) as a main component, a permanent antistatic agent, a metal salt (d) and / or an ionomer (e). The present invention provides a label for in-mold molding.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The in-mold molding label of the present invention will be described in more detail. Structure of label for in-mold molding: FIG. 1 is a sectional view of a label for hollow molding, in which 1 is a label for in-mold molding, 2 is printing, and 3 is a thermoplastic resin film substrate layer. (I), 4 is a heat-sealing resin layer (II)
It is. The surface of the heat-sealable resin layer (II) is embossed so that blistering of the label of the label pasting container can be prevented (Japanese Patent Laid-Open No. 2-84).
319, JP-A-3-260689).

FIG. 2 shows a thermoplastic resin film substrate layer (I) having a surface layer (B), a core layer (A) and a back layer (C), and embossing the heat-sealable resin layer. It is the elements on larger scale of the cross section of the label for in-mold molding of another mode. FIG. 3 shows another embodiment of in-mold molding in which a heat-sealing resin layer is embossed using a surface layer (B) and a core layer (A) as a thermoplastic resin film base layer (I). It is the elements on larger scale of the cross section of a label.

Thermoplastic resin film base layer (I) Thermoplastic resin film base layer (I) used in the present invention
Examples of the material include propylene resin, high density polyethylene, medium density polyethylene, poly 4-methylpentene-1,
Polyolefin resin such as ethylene-cyclic olefin copolymer, nylon-6, nylon-6,6, nylon-
6,10, polyamide resin such as nylon-6,12,
Polyethylene terephthalate resin, polyvinyl chloride resin, ABS resin, ionomer resin and the like can be mentioned. Preferably, the propylene resin, high density polyethylene, polyethylene terephthalate resin and the like have a melting point of 13%.
It is a thermoplastic resin in the range of 0 to 280 ° C, and these resins can be used as a mixture of two or more kinds.

It is preferable that the thermoplastic resin as the main component has a melting point higher by at least 15 ° C. than the melting point of the polyolefin resin constituting the heat-sealing resin layer (II). Among these resins, a propylene-based resin is preferable in terms of chemical resistance, cost, and the like. As such a propylene-based resin, a propylene homopolymer showing isotactic or syndiotactic stereoregularity, or propylene as a main component, and ethylene, butene-1, hexene-1, heptene-1,4 A copolymer with an α-olefin such as -methylpentene-1 is used. These copolymers may be binary, ternary, or quaternary, and may be random or block copolymers.

A film in which an inorganic fine powder and / or an organic filler is blended with these resins, a film stretched in one or two directions by a known method, a film coated with a latex containing an inorganic filler on the surface, A film on which aluminum is deposited or bonded can be suitably used. The type of the inorganic fine powder and / or the organic filler used in the thermoplastic resin film base layer is not particularly limited. Examples of the inorganic fine powder 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 moldability.

Examples of the organic filler include polyethylene terephthalate, polybutylene terephthalate, polyamide, polycarbonate, polyethylene naphthalate, polystyrene, melamine resin, polyethylene sulphite, polyimide, polyethyl ether ketone, polyphenylene sulphite, poly (4-methylpentene-1) and poly (4-methylpentene). Methyl methacrylate, a homopolymer of cyclic olefin, a copolymer of cyclic olefin and ethylene, etc., having a melting point of 12
0 ° C to 300 ° C or glass transition temperature of 120 ° C to
Those having a temperature of 280 ° C. are exemplified. One of the above-mentioned inorganic fine powders or organic fillers may be selected and 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 filler may be mixed and used.

The thermoplastic resin film substrate layer (I) of the present invention may be a single layer or a two-layer structure including the core layer (A) and the surface layer (B), May have a three-layer structure in which a surface layer (B) and a back layer (C) exist on the front and back surfaces, or may have a multilayer structure in which another resin film layer exists between the core layer (A) and the front and back surfaces. Alternatively, it may be stretched in at least one axial direction. When the multilayer structure is stretched, the number of stretching axes is one axis / one axis / three-layer structure.
1 axis, 1 axis / 1 axis / 2 axes, 1 axis / 2 axes / 1 axis, 2 axes / 1
Axle / 1 axis, 1 axis / 2 axes / 2 axes, 2 axes / 2 axes / 1 axis, 2 axes / 2 axes / 2 axes, and in the case of a layer structure of more than that, the number of stretching axes is arbitrary. Is combined with

Among these, from the viewpoints of dimensional stability at the time of printing, supply of the label into the mold, and prevention of heat shrinkage,
The thermoplastic resin film base layer (I) contains 5 to 30% by weight of an inorganic fine powder and / or an organic filler, 0 to 20% by weight of a high-density polyethylene, and 95 to 50% by weight of a propylene-based resin. One side of the biaxially stretched film core layer (A) of the resin composition
Alternatively, 15 to 65% by weight of an organic filler, 0 to 10% by weight of a high-density polyethylene and 85 to 2% of a propylene-based resin.
The surface layer (B) of the uniaxially stretched film of the resin composition containing 5% by weight of the core layer (A) opposite to the surface layer (B) is coated with an inorganic fine powder and / or an organic filler. A multilayer film to which a back layer (C) composed of a uniaxially stretched film of a resin composition containing 15 to 65% by weight, 0 to 10% by weight of high-density polyethylene and 85 to 25% by weight of a propylene-based resin is bonded. Or a uniaxial resin composition containing 5 to 45% by weight of an inorganic fine powder and / or an organic filler, 0 to 20% by weight of a high-density polyethylene and 95 to 35% by weight of a propylene-based resin. On one surface of the stretched film core layer (A), 15 to 65% by weight of an inorganic fine powder and / or an organic filler,
A multilayer film (see FIG. 3) to which a surface layer (B) of a uniaxially stretched film of a resin composition containing 0 to 10% by weight of high-density polyethylene and 85 to 25% by weight of a propylene-based resin is bonded. preferable.

In order to make the color of the container stand out,
When transparency is required for the label, the following thermoplastic resin film base layer (I) is also preferable. That is, a biaxially stretched film core layer of a resin composition containing 0 to 5% by weight of an inorganic fine powder and / or an organic filler, 0 to 20% by weight of a high-density polyethylene and 100 to 75% by weight of a propylene-based resin ( On one side of A), 1 to 30% by weight of an inorganic fine powder and / or an organic filler, 0 to 10% by weight of a high-density polyethylene and 9% of a propylene-based resin.
The surface layer (B) of the uniaxially stretched film of the resin composition containing 9 to 60% by weight is coated on one side of the core layer (A) opposite to the surface layer (B) with inorganic fine powder and / or organic layer. 1-30% by weight of filler, 0-1 high density polyethylene
A resin stretched film (see FIG. 2) to which a back layer (C) made of a uniaxially stretched film of a resin composition containing 0% by weight and 99 to 60% by weight of a propylene-based resin is bonded, or an inorganic fine powder. And / or 0 to 5% by weight of an organic filler, 0 to 20% by weight of high-density polyethylene and 100 to 75% by weight of a propylene-based resin on one side of a uniaxially stretched film core layer (A). , Inorganic fine powder and / or organic filler in 1-3
A stretched resin film to which a surface layer (B) of a uniaxially stretched film of a resin composition containing 0% by weight, 0 to 10% by weight of high-density polyethylene, and 99 to 60% by weight of a propylene-based resin is bonded (FIG. 3) is preferred.

In these multilayer films, printing is provided on the surface layer (B) side, and the heat-sealable resin layer (II) is provided on the core layer (A) or the back layer (C) side. The density of the multilayer film is preferably in the range of 0.60 to 1.20 g / cm ³ , and more preferably 0.65 to 1.10 g / cm ³ . Above thermoplastic resin film base layer (I)
Has a thickness of 20 to 250 μm, preferably 40 to 200 μm.
m. If the thickness is less than 20 μm, problems such as improper insertion of the label into the mold by the label inserter at a regular position and wrinkling of the label are likely to occur. Conversely, if it exceeds 250 μm, the strength at the boundary between the in-mold molded container and the label decreases, and the drop resistance of the container deteriorates. The thickness of each layer is
(A) layer is preferably 19 to 170 μm, more preferably 38 to 130 μm, and (B) layer is preferably 1 to 40 μm.
m, more preferably 2 to 35 μm, and the thickness of the layer (C) is preferably 0 to 40 μm, more preferably 0 to 35 μm.

Heat Sealable Resin Layer (II) (a) Polyolefin Resin The polyolefin resin constituting the heat sealable resin layer (II) has a density of 0.890 to 0.910 g /
cm ³ polypropylene random copolymer, density 0.
940-0.970 g / cm ³ high density polyethylene,
Low density to medium density high pressure method polyethylene having a density of 0.900 to 0.935 g / cm ³ , a density of 0.880 to
0.940 g / cm ³ linear linear polyethylene, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / acrylic acid alkyl ester copolymer,
Ethylene / methacrylic acid alkyl ester copolymer (alkyl group has 1 to 8 carbon atoms), metal salt of ethylene / methacrylic acid copolymer (Zn, Al, Li, K, Na, etc.)
For example, a polyethylene resin having a melting point of 50 to 130 ° C. is preferable.

More preferably, the crystallinity (X-ray method) is 1
0-60%, number average molecular weight 10,000-40,00
0 high pressure method polyethylene or linear linear polyethylene. Among them, ethylene 40 ~ 9 from the viewpoint of adhesiveness to the container
8% by weight and α-olefin having 3 to 30 carbon atoms
2% by weight of a metallocene catalyst, in particular a metallocene alumoxane catalyst, or, for example, WO 92/0
No. 1723, pamphlet etc., a linear linear polymer obtained by copolymerization using a catalyst comprising a metallocene compound and a compound which reacts with the metallocene compound to form a stable anion. Polyethylene is optimal. These polyolefin resins,
They may be used alone or as a mixture of two or more.
The content of the thermoplastic resin (a) in the heat-sealable resin layer (II) component is usually 50 to 95% by weight, preferably 60 to 93% by weight.

(B) Polyetheresteramide Polyetheresteramide constituting the heat-sealable resin layer (II) includes polyether esters disclosed in JP-A-58-11838 and JP-A-1-163234. Ester amides can be mentioned. Examples of (i) a salt of an aminocarboxylic acid or lactam having 6 or more carbon atoms or a diamine with a dicarboxylic acid having 6 or more carbon atoms, which are constituents of the polyetheresteramide, include ω-aminocaproic acid and ω-aminoenanthic acid. , Ω
-Amino carboxylic acids such as aminocaprylic acid, ω-aminopergonic acid, ω-aminocapric acid and 11-aminoundecanoic acid, 12-aminodedocanoic acid, or lactams such as caprolactam, enantholactam, caprylactam and laurolactam, and hexamethylenediamine Adipates, salts of diamine-dicarboxylic acids such as hexamethylenediamine-sebacate and hexamethylenediamine-isophthalate are used, and caprolactam, 12-aminododecanoic acid, and hexamethylenediamine-adipate are particularly preferably used. Can be

(Ii) Poly (alkylene oxide) glycol, which is a constituent component of polyetheresteramide, includes polyethylene glycol, poly (1,2-propylene oxide) glycol, poly (1,3-propylene oxide) glycol, and poly (alkylene oxide) glycol. (Tetramethylene oxide)
Glycol, poly (hexamethylene oxide) glycol, a block or random copolymer of ethylene oxide and polypropylene oxide, and a block or random copolymer of ethylene oxide and tetrahydrofuran are used. Among them, polyethylene glycol is particularly preferably used because of its excellent antistatic property. The poly (alkylene oxide) glycol has a number average molecular weight of 200 to 6,000, particularly 250 to 4,000. If the number average molecular weight is less than 200, the resulting polyetheresteramide has poor mechanical properties and a number average molecular weight of 6 ,
If it exceeds 000, it is not preferable because the antistatic property is insufficient.

(Iii) Dicarboxylic acids having 4 to 20 carbon atoms which are constituents of the polyetheresteramide include terephthalic acid, isophthalic acid, phthalic acid, naphthalene-2,6-dicarboxylic acid, and naphthalene-2,7. Aromatic dicarboxylic acids such as dicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, diphenoxyethane dicarboxylic acid and sodium 3-sulfoisophthalate, 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid and dicyclohexyl Alicyclic dicarboxylic acids such as -4,4'-dicarboxylic acid and aliphatic dicarboxylic acids such as succinic acid, oxalic acid, adipic acid, sebacic acid and dodecanediacid (decanedicarboxylic acid);
In particular, terephthalic acid, isophthalic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid and dodecanediacid are preferably used from the viewpoint of polymerizability, color tone and physical properties.

The (ii) poly (alkylene oxide) glycol and (iii) dicarboxylic acid react in a molar ratio of 1: 1 in the reaction, but are usually supplied at different charging ratios depending on the type of dicarboxylic acid used. (Ii) poly (alkylene oxide) glycol and (iii) dicarboxylic acid, which are constituents of polyetherester, are constituent units of polyetheresteramide and are used in the range of 90 to 10% by weight. Is poor in mechanical properties of polyetheresteramide, and if it is less than 10% by weight, the obtained resin has poor antistatic properties, which is not preferable.

The polymerization method of the polyetheresteramide is not particularly limited. For example, (i) a polyamide prepolymer having a carboxylic acid group at both ends by reacting (i) an aminocarboxylic acid or a lactam with (iii) a dicarboxylic acid; And (ii) a method of reacting poly (alkylene oxide) glycol under vacuum, (b) charging each of the compounds (i), (ii) and (iii) into a reaction vessel and reacting in the presence of water. Or a method in which a carboxylic acid-terminated polyamide prepolymer is formed by performing a pressure reaction at a high temperature in the absence of the compound, and then the polymerization is allowed to proceed under normal pressure or reduced pressure. A method in which the compound of iii) is simultaneously charged into a reaction vessel, melt-mixed, and then the polymerization is allowed to proceed at once in a high vacuum can be used.

There is no limitation on the polymerization catalyst. For example, antimony catalysts such as antimony trioxide, tin catalysts such as monobutyltin oxide, titanium catalysts such as tetrabutyl titanate, and zirconate catalysts such as tetrabutyl zirconate. And the like can be used alone or in combination of two or more. The content of the polyetheresteramide (b) in the heat-sealing resin layer (II) component is as follows:
Usually, it is 5 to 35% by weight, preferably 6 to 30% by weight. When the amount of the component (b) is less than the above range, the antistatic property of the heat-sealable resin layer (II) is insufficient,
Exceeding the above range results in low fusion force of the label to the container.

(C) Polyamide resin As a component of the heat-sealable resin layer (II), the ring-opening weight of a lactam having 6 to 12 or more carbon atoms for the purpose of more stably exhibiting antistatic performance. A polycondensate of an aminocarboxylic acid having 6 to 12 or more carbon atoms and a dicarboxylic acid having 4 to 20 carbon atoms and 6 to 12 carbon atoms
Alternatively, a polyamide resin (c) such as a polycondensate of a diamine or more can be contained.

Specifically, nylon 66, nylon 6
9, nylon 610, nylon 612, nylon 6, nylon 11, nylon 12, nylon 46 and the like. In addition, nylon 6/66, nylon 6/1
Copolymer polyamides such as 0, nylon 6/12, and nylon 6/66/12 can also be used. Further, aromatic-containing polyamides obtained from aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid and meta-xylene diamine or aliphatic diamines can be mentioned. Of these, particularly preferred are nylon 66, nylon 6, and nylon 12. Heat sealing resin layer (I
The content of the polyamide resin (c) in the component (I) is usually 0.
10 to 10% by weight, preferably 0 to 8% by weight. When the content of the component (c) exceeds the above range, the fusion force of the label to the container is low.

(D) Metal salt The metal constituting the metal salt in the present invention is Li,
Na, K, Rb, Cs, Be, Mg, Ca, Sr, B
a, Ti, Zr, Mn, Fe, Co, Ni, Cu, Z
n, Al, etc., and particularly Na, Ca, Mg, Z
n, Zr, and Al are preferred. On the other hand, groups that form salts with the above metals include nitric acid, sulfuric acid, acetic acid, chloric acid, perchloric acid, carbonic acid, oxalic acid, silicic acid, phosphoric acid, boric acid, cyanic acid, halogen, chloric acid, thiocyanate Acid, hydroxyl, oxygen, etc. are mentioned, and among these, perchloric acid, hydroxyl, phosphoric acid, acetic acid, oxygen, carbonic acid, and silicic acid are preferable.

Specifically, sodium chlorate, sodium perchlorate, calcium hydroxide, magnesium hydroxide,
Aluminum hydroxide, zinc hydroxide, zirconium hydroxide, sodium phosphate, calcium oxide, magnesium oxide, aluminum oxide, zinc oxide, calcium carbonate,
Basic calcium carbonate, magnesium carbonate, basic magnesium carbonate, aluminum carbonate, zinc carbonate, potassium silicate, sodium silicate, calcium silicate, magnesium silicate and the like, among which sodium chlorate, sodium perchlorate, Calcium hydroxide, magnesium hydroxide, zirconium hydroxide, calcium oxide, magnesium oxide, and sodium phosphate are preferred. The content of the metal salt (d) in the heat-sealing resin layer (II) component is usually 0.01 to 5% by weight, preferably 0.1 to 5% by weight.
3% by weight. When the content of the component (d) is less than the above range, the antistatic property of the heat-sealable resin layer (II) is insufficient. When the content exceeds the above range, the fusion force of the label to the container is low.

(E) Ionomer The ethylene ionomer resin used in the present invention is:
It is an ionic polymer obtained by adding a metal ion having a valence of 1 to 3 to a copolymer of ethylene and an α, β-unsaturated carboxylic acid derivative. Here, examples of the α, β-unsaturated carboxylic acid derivative include acrylic acid, methacrylic acid, itaconic acid, maleic acid, ethyl acrylate, isobutyl acrylate, methyl methacrylate, methyl hydrogen maleate, and the like. Representative examples of the metal ions having a valence of 1 to 3 include Na +, K +, Mg ++, Zn ++, Al +++, and the like. As these ethylene ionomer resins, various grades which are generally sold under the trade names "Surlyn" and "Himilan" can be used.

Among these, an ethylene ionomer resin in which the metal ion is Zn ion significantly improves the affinity between polyetheresteramide and polyolefin, and as a result, the mechanical properties of the resin composition of the present invention are excellent. Is preferably used. Further, an ethylene ionomer resin in which the metal ion is Na ion is particularly preferably used in that the antistatic property of the resin composition of the present invention is improved. Further, an ionomer resin in which the metal ion is a Na ion and another metal ion, for example, an ethylene ionomer resin containing at least two kinds of metal ions such as Zn ions, or an ethylene ionomer resin in which the metal ion is a Na ion, and the metal ion is Na A mixture with a metal ion other than the ion, for example, an ethylene ionomer resin such as a Zn ion is particularly preferable because both the mechanical properties and the antistatic property of the resin composition of the present invention are excellent. The above ionomer (e) in the component of the heat-sealable resin layer (II)
Is usually 0.5 to 10% by weight, preferably 1 to 10% by weight.
5% by weight. When the content of the component (e) is less than the above range, the antistatic property of the heat-sealable resin layer (II) is insufficient, and when the content exceeds the above range, the fusion force of the label to the container is low. The heat-sealable resin layer (II) may simultaneously contain the metal salt (d) and the ionomer (e).

Optional Components To the heat-sealable resin of the present invention, other known resin additives can be optionally added as long as the desired heat-sealability and antistatic properties are not impaired. Examples of the additive include a dye, a nucleating agent, a plasticizer, a release agent, an antioxidant, a flame retardant, and an ultraviolet absorber. The thickness of the heat-sealable resin layer (II) is in the range of 0.5 to 20 μm, preferably 1 to 10 μm. This thickness is required to be 1 μm or more in order for the heat-sealable resin layer (II) to be melted by the heat of the molten polyethylene such as parison or polypropylene at the time of the hollow molding and the molded article container and the label to be firmly fused together. If the thickness exceeds 10 μm, the label curls, making it difficult to perform offset printing and fixing the label to a mold, which is not preferable.

As described above, the heat-sealing resin layer of the label is disclosed in JP-A-2-84319 and JP-A-3-260 in order to prevent the occurrence of blisters at the time of hollow molding.
Embossing can be performed as disclosed in JP-A-689. The embossed pattern is, for example, 2.54 cm
An embossing process of 5 to 200 lines per line, and a reverse gravure type pattern is preferable. If necessary, these in-mold-forming labels can improve the printability of the surface of the thermoplastic resin base material layer (I) by corona discharge machining or the like, or a known coating. Printing includes gravure printing, offset printing, flexo printing, screen printing,
Inkjet printing, electrophotographic printing, and the like can be performed to specify the barcode, manufacturer, sales company name, character, product name, usage, and the like. The printed label (1) is separated into labels having required dimensions by punching. This label for in-mold molding is usually manufactured as a blank surrounding the side surface of a cup-shaped container, and is manufactured as a label attached to the front side and / or the back side of a bottle-shaped container in blow molding.

(In-Mold Molding) The label for in-mold molding is placed on the inner wall of the lower female mold of the differential pressure molding die so that the printed surface of the label is in contact with the inner surface of the lower mold, and then suctioned onto the inner wall of the mold. The melt of the resin sheet of the container molding material is fixed and then guided to the upper part of the lower female mold, and subjected to differential pressure molding by a conventional method, thereby forming a label bonding container in which the label is integrally fused to the container outer wall. . As the differential pressure molding, either vacuum molding or pressure molding can be adopted, but in general, both are used in combination, and differential pressure molding using plug assist is preferable. In addition, this label can be particularly suitably used as an in-mold label for hollow molding, in which a molten resin parison is pressed against the inner wall of a mold by air pressure. In the label-laminated container manufactured in this manner, the label (1) is fixed in the mold, and then the label and the resin container are integrally formed.
The container (1) has a strong adhesive strength between the container body and the label (1), has no blister, and has a good appearance decorated with the label.

[0036]

The present invention will be described more specifically with reference to the following examples and comparative examples. The materials, amounts used, ratios, operations, and the like shown below can be changed as appropriate unless exempted from the present invention. Therefore, the scope of the present invention is not limited to the following specific examples. [I] Measurement and evaluation methods of physical properties Measurement and evaluation of physical properties in Examples and Comparative Examples were carried out by the following methods. (1) Measurement of physical properties: (a) MFR: compliant with JIS-K-7210 (b) Density: compliant with JIS-K-7112 (c) Opacity: compliant with JIS-Z-8722 (d) Surface resistivity : The surface specific resistance of the heat-sealable resin layer (II) side of the label was measured in an atmosphere at 20 ° C. and a relative humidity of 50%.

(2) In-mold molding: A label printed by UV offset printing was cut and punched after 3 days, and evaluated by in-mold molding. As a comparison, those stored at room temperature and those subjected to heat treatment in a 40 ° C. oven for one month assuming high-temperature storage in a warehouse or the like in summer were also used. (E) Bonding strength of the label to the container: The label attached to the container by blow molding was cut to a width of 15 mm, and the adhesive strength between the label and the container was measured using a tensile tester “Autograph AGS-D” manufactured by Shimadzu Corporation. The shape was determined by T-peeling at a tensile speed of 300 mm / min. The criteria for label use are as follows. 400 (g / 15 mm) or more: no problem in practical use 200 to 400 (g / 15 mm): slightly weak adhesion, but no problem in practical use 200 or less (g / 15 mm): problem in practical use

(3) Paper feedability in offset printing: (f) Using a diamond-II type printing machine manufactured by Mitsubishi Heavy Industries, Ltd., using a UV ink at 25 ° C. and a relative humidity of 40% in an environment of Kikuhan. With the paper size of the plate (636 mm x 470 mm),
1000 sheets were continuously printed at a speed of 7000 sheets / hour. At this time, the number of times the machine was stopped due to a trouble (sheet insertion or paper misalignment) in the sheet discharging device was determined based on the following criteria. ○: Machine does not stop even once △: Machine stops 1 to 3 times ×: Machine stops 4 or more times

[II] Experimental Example [Production of polyetheresteramide] 55 parts of 12-aminododecanoic acid, 40 parts of polyethylene glycol having a number average molecular weight of 1,000 and 15 parts of adipic acid were combined with "Irganox 1098" (oxidized). Inhibitor) together with 0.2 part of antimony trioxide catalyst and 0.1 part of an antimony trioxide catalyst were charged into a reaction vessel equipped with a helical ribbon stirring blade.
After heating and stirring for 0 minutes to obtain a transparent homogeneous solution,
Polymerization was conducted for 4 hours at a temperature of 0.5 ° C. or less at 0.5 ° C. to obtain a viscous and transparent polymer. The polymer was discharged in a gut shape on a cooling belt and pelletized to prepare a pellet-like polyetheresteramide (b1).

For b1, 50 parts of ε-caprolactam, 40 parts of polyethylene glycol having a number average molecular weight of 1,000 and 10 parts of dodecanediacid were used together with 0.2 part of “Irganox 1098” and 0.02 part of antimony trioxide. After charging into a reaction vessel and purging with nitrogen and heating and stirring at 260 ° C. for 60 minutes to form a transparent homogeneous solution, the pressure in the reaction vessel was reduced to 500 mmHg to remove water in the gas phase of the reaction vessel, and 0.08 part of tetrabutyl zirconate was added. Was added. Then at 260 ° C, 0.5
Polymerization was performed for 3 hours under the condition of mmHg or less to obtain a viscous and transparent polymer. Thereafter, a polyetheresteramide (b2) was prepared in the same manner as in b1.

[Production Example of Label] (Example 1) (1) Novatec PP, MA-8, a propylene homopolymer manufactured by Nippon Polychem Co., Ltd. (trade name, melting point: 164)
C) 67% by weight, high density polyethylene "Novatech HD, HJ580" manufactured by Nippon Polychem Co., Ltd. (trade name, melting point 1)
34 ° C., after which melt-kneaded using density 0.960g / cm ³⁾ 10 wt% and heavy calcium carbonate powder 23 wt% from the synthetic resin composition having a particle size of 1.5μm (A) is an extruder, a die The sheet was extruded at a temperature of 250 ° C., and the sheet was cooled to a temperature of about 50 ° C. Next, after heating this sheet to about 153 ° C., it was stretched four times in the machine direction using the peripheral speed of the roll group to obtain a uniaxially stretched film.

(2) Separately, Nippon Polychem Co., Ltd.
Len homopolymer "Novatech PP, MA-3" (product
Name: melting point 165 ° C) 51.5% by weight, density 0.950g
/ Cm ^Three3.5-layer high-density polyethylene "HJ580"
%, Heavy calcium carbonate powder having a particle size of 1.5 μm, 42 layers
%, A titanium oxide powder having a particle diameter of 0.8 μm
The composition (B) was melt mixed at 240 ° C. using another extruder.
Kneaded, and this is applied to the surface of the longitudinally stretched film by a die.
Extruded into a layered shape, laminated (B / A), and surface layer / core
A layer stack was obtained.

(3) MFR obtained by copolymerizing ethylene and 1-hexene using a metallocene catalyst is 18 g / 10
.1-hexene copolymer having a density of 0.898 g / cm ³ and a melting point of 90 ° C. (1-hexene content 22
Weight%, crystallinity 30, number average molecular weight 23,000) 6
0% by weight, MFR 4 g / 10 min, density 0.92 g
/ Cm ³ , high-pressure low-density polyethylene 3 with a melting point of 110 ° C
After mixing 90% by weight of a mixture of 0% by weight, 9.5% by weight of the polyetheresteramide (b1) obtained in the above Production Example and 0.5% by weight of sodium perchlorate for 3 minutes using a tumbler mixer, The mixture was kneaded with a twin-screw extruder equipped with a vent set at a temperature of 230 ° C., extruded into a strand shape from a die and cut to obtain pellets (II) for a heat-sealing resin layer.

(4) Propylene homopolymer "MA-3"
51.5% by weight, high density polyethylene "HJ580"
3.5% by weight, 42% by weight of heavy calcium carbonate powder having a particle size of 1.5 μm and titanium oxide powder 3 having a particle size of 0.8 μm
% Of the composition (C) and the pellets (II) for the heat-sealable resin layer using different extruders.
The mixture was melt-kneaded at 0 ° C., supplied to one co-extrusion die, laminated at 230 ° C. in the die, and extruded into a film. On the layer side, extrude so that the heat-sealable resin layer (II) is on the outside,
This was passed through an embossing roll (150 lines per inch, reverse gravure type) composed of a metal roll and a rubber roll, and a pattern with an interval of 0.17 mm was embossed on the heat-sealable resin layer side.

The four-layer film (B / A / C / II) was introduced into a tenter oven and reheated to 155 ° C.
The film was stretched 7 times in the transverse direction and subsequently heat-set at 164 ° C., cooled to 55 ° C., and the ears were slit. Further surface layer (B layer) side was corona discharge treatment of 70 W / m ² / min. It has a density of 0.79 g / cm ³ and a thickness of 10
0 μm (thickness of each layer B / A / C / II = 30/40/25)
/ 5 μm) to obtain a multilayer film having a four-layer structure. The surface average roughness (R) of this film on the heat seal layer (II) side
When a) was measured with a surface roughness meter (Surfcoder SE-30, manufactured by Kosaka Laboratory Co., Ltd.), it was 2.5 μm. When UV offset printing was performed on the surface layer (B) side of the four-layered multilayer film in an environment of 25 ° C. and a relative humidity of 40%, static electricity was little generated, so that printing was smoothly fed and discharged. There was no stop on the way. The paper surface temperature at this time had reached 60 ° C.

This was cut and punched out three days later, and a label for in-mold molding (width: 70 mm, length: 90 m)
m) and, for comparison, unprinted labels stored at room temperature and labels stored for one month in an oven at 40 ° C. were vacuumed into one of the molds for blow molding using an automatic label supply device. After fixing using a mold so that the printing surface side is in contact with the mold, high-density polyethylene (having a melting point of 134) is used.
C) is melt-extruded at 200 ° C., and then the split mold is clamped. Then, 4.2 kg / cm ² of compressed air is supplied into the parison, and the parison is expanded and brought into close contact with the mold to form a container. After being fused with the label for in-molding and then cooling the mold, the mold was opened to take out the hollow container to which the label was attached. Table 1 shows the occurrence of blisters and the adhesive strength of the label at this time.

(Examples 2 to 5, Comparative Examples 1 to 5) Example 1
, A label for in-mold molding was obtained in the same manner as in Example 1, except that the composition of the heat-sealable resin layer (II) was changed to that shown in Table 1. Table 1 shows the results of the evaluation.

(Example 6) Tree for core layer in Example 1
Fat composition (A), resin composition for surface layer (B), and table
Pellet for heat-sealable resin layer by blending described in 1.
(II) at 250 ° C., 240 ° C., 230
After melt-kneading in another extruder set to
And laminated and extruded so that B / A / II is obtained.
After cooling to 0 ° C., a sheet having a three-layer structure was obtained. This sheet
After heating to 120 ° C, the metal roll and rubber roll
Embossing roll (200 lines per inch, reverse
Rubier type) and 0.13 on the heat-sealable resin layer side.
The pattern at the interval of mm was embossed. Then the same temperature
The film was stretched 6 times in the machine direction in the machine direction. Then 50 ° C
After cooling, the ears were slit and the surface layer (B
Layer) side, 50W / m^Two/ Min corona discharge treatment.
Its density is 0.91 g / cm ^Three90μm thick
(Thickness of each layer B / A / II = 5/80/5 μm)
Was obtained. Heat sealing this film
The surface average roughness (Ra) on the layer (II) side is 2.4 μm.
Was. Table 1 shows the results of the evaluation.

Example 7 (1) Novatec PP, MA-8, a propylene homopolymer manufactured by Nippon Polychem Co., Ltd. (trade name, melting point: 164)
C) 88% by weight, high-density polyethylene "Novatech HD, HJ580" manufactured by Nippon Polychem Co., Ltd. (trade name, melting point 1)
34 ° C., after which melt-kneaded using density 0.960g / cm ³⁾ 10 wt% and heavy calcium carbonate powder 2 wt% from the synthetic resin composition having a particle size of 1.5μm (A) is an extruder, a die Extruded into a sheet at a temperature of 250 ° C., about 5
The sheet was cooled to a temperature of 0 ° C. Then
After heating this sheet to about 153 ° C., it was stretched four times in the machine direction using the peripheral speed of the roll group to obtain a uniaxially stretched film.

(2) Separately, 85% by weight of propylene homopolymer “Novatec PP, MA-3” (trade name; melting point: 165 ° C.) manufactured by Nippon Polychem Co., Ltd., density: 0.950 g / c
high density polyethylene "HJ580" 5 wt% of m ^3, and melt-kneaded at 240 ° C. using a separate extruder heavy calcium carbonate powder 10 wt% from a composition with a particle size 1.5 [mu] m (B), which Was extruded from the die into a film shape on the surface of the longitudinally stretched film and laminated (B / A) to obtain a surface layer / core layer laminate.

(3) Propylene homopolymer "MA-3"
Composition (C) comprising 88% by weight, 10% by weight of high-density polyethylene "HJ580", 2% by weight of heavy calcium carbonate powder having a particle size of 1.5 [mu] m, and a heat-sealing resin layer having the composition shown in Table 1 The pellets for (II) are melt-kneaded at 230 ° C. using different extruders, supplied to one co-extrusion die, laminated at 230 ° C. in the die, and extruded into a film. / Heat-sealable resin layer (II) on layer A side of laminate (B / A) for core layer
And embossed in the same manner as in Example 1.

The four-layer film (B / A / C / II) was guided to a tenter oven and reheated to 160 ° C.
The film was stretched 7 times in the transverse direction and subsequently heat-set at 164 ° C., cooled to 55 ° C., and the ears were slit. Further, the surface layer (layer B) was subjected to a corona discharge treatment at 70 W / m ² / min. It has a density of 0.90 g / cm ³ and a wall thickness of 80.
μm (thickness of each layer B / A / C / II = 20/40/15 /
5 μm) was obtained. Surface average roughness (Ra) of this film on the heat seal layer (II) side
Was 2.3 μm, and the opacity according to JIS-Z-8722 was 15%. Table 1 shows the results of the evaluation.

Example 8 The resin composition for a core layer (A), the resin composition for a surface layer (B) and the pellets for a heat-sealable resin layer (II) in Example 7 were each used for 250 parts.
After melting and kneading with another extruder set at 240 ° C., 240 ° C., and 230 ° C., laminating and extruding in a die so as to obtain B / A / II, cooling to 70 ° C., and 3 layers A sheet of structure was obtained. Density in the same manner except that of Embodiment 6 is 0.90 g / cm ^3, the thickness is 80 [mu] m (thickness of each layer B / A
/ II = 5/70/5 μm) to obtain a uniaxially stretched film having a three-layer structure. The surface average roughness (Ra) of this film on the heat seal layer (II) side is 2.1 μm, and the JIS-Z
The opacity according to -8722 was 8%. Table 1 shows the results of the evaluation.

[0054]

[Table 1]

[0055]

According to the present invention, even when heating during printing during label production, particularly UV offset printing, and during storage for a long period of time, especially at high temperatures in the summer, there is no decrease in heat sealability and the resin is melted firmly. A label for in-mold molding which has good anti-static properties, and has excellent printing, cutting, punching, and insertability into a mold throughout the year can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an in-mold molding label according to one embodiment of the present invention.

FIG. 2 is a sectional view of an in-mold molding label according to another embodiment of the present invention.

FIG. 3 is a sectional view of an in-mold molding label according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 In-mold label 2 Printing 3 Thermoplastic resin film base material layer (I) 4 Heat-sealing resin layer (II) 5 Embossed pattern peak 6 Embossed pattern valley

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] February 22, 2001 (2001.2.2)
2)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0036

[Correction method] Change

[Correction contents]

[0036]

The present invention will be described more specifically with reference to the following examples and comparative examples. The materials, amounts used, ratios, operations, and the like shown below can be changed as appropriate unless exempted from the present invention. Therefore, the scope of the present invention is not limited to the following specific examples. [I] Measurement and evaluation methods of physical properties Measurement and evaluation of physical properties in Examples and Comparative Examples were carried out by the following methods. (1) Measurement of physical properties: (a) MFR: compliant with JIS-K-7210 (b) Density: compliant with JIS-K-7112 (c) Opacity: compliant with JIS-P-8138 (d) Surface resistivity : The surface specific resistance of the heat-sealable resin layer (II) side of the label was 20 ° C. and the relative humidity was 50%.
It measured under the atmosphere of.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0052

[Correction method] Change

[Correction contents]

The four-layer film (B / A / C / II) was guided to a tenter oven and reheated to 160 ° C.
The film was stretched 7 times in the transverse direction and subsequently heat-set at 164 ° C., cooled to 55 ° C., and the ears were slit. Further, the surface layer (layer B) was subjected to a corona discharge treatment at 70 W / m ² / min. It has a density of 0.90 g / cm ³ and a wall thickness of 80.
μm (thickness of each layer B / A / C / II = 20/40/15 /
5 μm) was obtained. Surface average roughness (Ra) of this film on the heat seal layer (II) side
Was 2.3 μm, and the opacity according to JIS-P-8138 was 15%. Table 1 shows the results of the evaluation.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0053

[Correction method] Change

[Correction contents]

Example 8 The resin composition for a core layer (A), the resin composition for a surface layer (B) and the pellets for a heat-sealable resin layer (II) in Example 7 were each used for 250 parts.
After melting and kneading with another extruder set at 240 ° C., 240 ° C., and 230 ° C., laminating and extruding in a die so as to obtain B / A / II, cooling to 70 ° C., and 3 layers A sheet of structure was obtained. Otherwise, in the same manner as in Example 6, the density was 0.90 g / cm ³ and the wall thickness was 80 μm (each layer thickness B / A
/ II = 5/70/5 μm) to obtain a uniaxially stretched film having a three-layer structure. The surface average roughness (Ra) on the heat seal layer (II) side of this film is 2.1 μm, and the JIS-P
The opacity according to -8138 was 8%. Table 1 shows the results of the evaluation.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B29K 23:00 B29K 23:00 B29L 9:00 B29L 9:00 F Term (Reference) 4F100 AA01H AA02B AA08 AK01A AK01B AK01C AK01D AK01H AK03B AK05 AK07 AK41B AK41J AK46B AK46J AK54B AK54J AK62 AK70B AK80B AL01B AL05B BA02 BA04 BA07 BA10A BA10B CA22B CA23A CA23C CA23D DD07B DE01H EH20 EJ37A EJ37C EJ37D EJ40B GB90 HB31B JA04B JA07B JA11B JB16A JB16C JB16D JG03 JJ03 JL01 JL11 JL12B 4F206 AA03 AA22 AA24E AA29E AA32E AB09 AB11 AB16 AD09 AF01 AF16 AG03 JA07 JB19 4F208 AA03 AA22 AA24E AA29E AA32E AB09 AB11 AB16 AC03 AF01 AF16 AG03 AH55 AM28 LA01 LA02 LB01 LB19 LD14 LG05 LG06 LG26 LH17 LJ05 LJ23 LJ L

Claims (7)

[Claims] 1. A multilayer film comprising a thermoplastic resin film base layer (I) and a heat-sealable resin layer (II), wherein the heat-sealable resin layer (II) is a polyolefin-based resin (a) Characterized by comprising a thermoplastic resin composition containing a permanent antistatic agent mainly composed of an ether ester amide (b), a metal salt (d) and / or an ionomer (e), for in-mold molding. label. 2. The heat-sealable resin layer (II) comprises: Component a: 50 to 95% by weight of a polyolefin resin Component b: 5 to 35% by weight of a polyetheresteramide Component c: 0 to 10% by weight of a polyamide Component d: The in-mold molding label according to claim 1, comprising a resin composition containing 0.01 to 5% by weight of a metal salt. 3. The in-mold molding according to claim 1, wherein the heat-sealable resin layer (II) comprises a resin composition containing Component e: 0.5 to 10% by weight of an ionomer. For labels. 4. The polyolefin resin of component a has a crystallinity of 10 to 60% and a number average molecular weight of 10,000 to 4
The label for in-mold molding according to any one of claims 1 to 3, wherein the label is polyethylene having a molecular weight of 0000 and a melting point of 50 to 130 ° C. 5. The label for in-mold molding according to claim 1, wherein the heat-sealing resin layer (II) has an embossed surface. 6. The thermoplastic resin film base layer (I) comprises:
The label for in-mold molding according to any one of claims 1 to 5, comprising a film stretched in at least one direction. 7. The thermoplastic resin film base layer (I)
The label for in-mold molding according to any one of claims 1 to 6, comprising a multilayer film containing an inorganic and / or organic filler.