JPH11296089A - Pressure-sensitive adhesive label - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a pressure-sensitive adhesive label which is excellent in not only the adhesiveness of a polyester film and laminated films but the adhesiveness to a printing layer as well and is excellent in adhesiveness even after a treatment at a high temp. and high humidity by using a specific resin compsn. as the laminated films provided with the printing layer. SOLUTION: This label is formed by providing the one surface of the polyester film with the pressure-sensitive adhesive layer and the other surface with the printing layer on the laminated films. The laminated films consist of a resin, melamine crosslinking agent and oxazoline crosslinking agent as essential constitution components. The resin is at least one kind selected from among an acrylic resin, polyester resin and urethane resin. The laminated films are preferably formed by compounding 0.2 to 20 pts.wt. melamine crosslinking agent and 0.2 to 20 pts.wt. oxazoline crosslinking agent with the resin in the form that the weight ratio [oxazoline crosslinking agent]/[melamine crosslinking agent] in the crosslinking agent is within a range of 0.1 to 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a polyester film provided with a laminated film and has excellent adhesiveness to a printed layer provided, and at the same time, has an adhesive property even after treatment under high temperature and high humidity. The present invention relates to a pressure-sensitive adhesive label having excellent performance.

[0002]

2. Description of the Related Art Generally, labels are used for many purposes such as food, medicine, electronics, medical care, information industry, and daily goods for purposes such as quality display, quality assurance, price tags, and advertising.

[0003] Above all, adhesive labels include no gum labels,
Compared to labels such as gluing labels, gum labels, screw-on labels, heat seal labels, etc., they are relatively well attached to various types of adherends and are easy to use. Following. In the future, labels with high adhesive levels for automobiles, building materials, etc., fine labels with high precision such as those for computers, practical labels with ideas for everyday goods and office supplies, etc. Is expected to expand further.

The basic configuration of this adhesive label is such that a surface substrate, an adhesive layer, and a release paper are laminated in this order. Printing is performed on the surface substrate as necessary,
When actually used, the release paper that functions as a conveyor for protecting the pressure-sensitive adhesive layer and performing processing such as printing on the label is released.

As the surface substrate, paper, plastic film, cloth, metal and the like are used. Among them, plastic films such as vinyl chloride film, polyester film, polypropylene film and polyethylene film are widely used. In particular, biaxially oriented polyester film is a plastic film that has recently received the most attention because it has excellent properties such as mechanical properties, dimensional stability, heat resistance, and electrical properties as compared with other plastic films. .

However, the biaxially oriented polyester film generally has a disadvantage that the surface is highly crystallographically oriented and has poor adhesion to various paints and inks used for printing adhesive labels. For this reason, conventionally, studies have been made to perform surface treatment on the polyester film surface by various methods to improve printing characteristics and adhesiveness.

As a method for imparting adhesiveness to the printing layer, for example, a surface activation method of performing corona discharge treatment, ultraviolet irradiation treatment, plasma treatment or the like on the surface of the base polyester film, a chemical agent such as an acid, alkali, amine aqueous solution or the like. And a method of providing various resins such as acrylic resin, polyester resin, urethane resin, and polyolefin resin as a primer layer on the film surface. Among them, in particular, as a method of providing the primer layer by application and imparting adhesiveness, a coating liquid containing the resin component is applied to a polyester film before completion of crystal orientation, dried, stretched, and heat-treated. A method of performing crystal orientation by performing the method (in-line coating method) is considered to be promising in terms of process simplification and manufacturing cost, and is performed in the art.

[0008] In particular, the above-mentioned method can be carried out in the process of producing a polyester film, is advantageous in terms of cost, and is capable of selecting and coating an adhesive substance which can cope with various coatings. And those obtained by laminating a water-soluble or water-dispersible polyester resin, acrylic resin, urethane resin or the like as an adhesive substance on a polyester film (JP-A-55-15825, JP-A-58-77861, 1960-24
No. 8232, JP-A-62-204940, JP-A-1-108037, etc.).

Above all, when a polyester resin is provided as a primer layer, the laminated polyester film is substantially composed of the polyester resin in both the base polyester film and the laminated film. Slit scraps or defective products are collected and easily used again as a film raw material, which is advantageous in terms of cost and quality. Therefore, a number of methods have been proposed (JP-A-60-1952).
No. 2, JP-A-60-89334, JP-A-60-89334
-198240, JP-A-62-152850, etc.).

[0010]

However, the above-mentioned prior art has the following problems.

When an acrylic resin or a urethane resin is laminated to impart adhesiveness, the adhesiveness to various coatings and inks as coatings is excellent, but the adhesiveness to the base polyester film becomes insufficient. In recent years, as adhesive labels have been used in a wide range of applications, there has been a situation in which the adhesion to the printing layer has been insufficient under severe conditions that could not be imagined until now, for example, under high temperature and high humidity. It's happening more and more. In addition, when a polyester resin is laminated, the adhesion to the base material is good, but the adhesion to the ink tends to be poor, and, similarly to the above, the printing layer is also formed under high temperature and high humidity. Often lacks adhesiveness.

As a method for improving the adhesiveness under high temperature and high humidity, a method of crosslinking a resin to improve the adhesiveness is generally considered. For example, there is an acrylic resin, a urethane resin, or a polyester resin to which a melamine-based crosslinking agent, an isocyanate-based crosslinking agent, or an epoxy-based crosslinking agent is added. However, there has not been obtained any ink which has both ink adhesiveness and adhesiveness under high temperature and high humidity.

In the case where a laminated film composed of two or more kinds of polyester resins is provided on a base polyester film, a wide range of ink adhesiveness can be obtained, but in particular, in terms of adhesiveness under high temperature and high humidity. Satisfaction has not been obtained.

[0014] In view of these drawbacks of the prior art, the present invention is excellent in not only the adhesion between the base polyester film and the laminated film but also the adhesion to the printed layer, and at the same time, the treatment under high temperature and high humidity. It is intended to provide a pressure-sensitive adhesive label having excellent adhesive properties.

[0015]

The present invention employs the following means to solve the above-mentioned problems. That is, the pressure-sensitive adhesive label of the present invention is a pressure-sensitive adhesive label in which a pressure-sensitive adhesive layer is provided on one surface of a polyester film provided with a laminated film on at least one surface, and a printing layer is provided on the laminated film on the other surface. The laminated film comprises a resin, a melamine-based crosslinking agent and an oxazoline-based crosslinking agent as main components.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention has been made to solve the above-mentioned problem, that is, it is excellent not only in adhesion between a polyester film as a base material and a laminated film, but also in adhesion to a printed layer, and at the same time, treatment under high temperature and high humidity. Even after that, the present inventors have conducted intensive studies on pressure-sensitive adhesive labels having excellent adhesive properties and have used a specific resin composition as a laminated film. As a result, they have surprisingly found out that these problems can be solved all at once.

In the polyester film according to the pressure-sensitive adhesive label of the present invention, polyester is a general term for polymers having an ester bond as a main bonding chain, and preferred polyesters include ethylene terephthalate, propylene terephthalate, and ethylene. −2,6-naphthalate, butylene terephthalate, propylene-2,6-
Those having at least one component selected from naphthalate, ethylene-α, β-bis (2-chlorophenoxy) ethane-4,4′-dicarboxylate as a main component can be used. These components are 1
Although only one kind may be used or two or more kinds may be used in combination, it is particularly preferable to use a polyester containing ethylene terephthalate as a main constituent component when comprehensively judging quality, economy and the like. In applications in which heat acts on the base material or in applications in which an ultraviolet curable resin is used as the printing layer of the pressure-sensitive adhesive label and the resin shrinks during curing, polyethylene-2,6 having excellent heat resistance and rigidity is used. -Naphthalate is more preferred.

Further, these polyesters may further contain some other dicarboxylic acid component or diol component, preferably 2 or more.
0 mol% or less may be copolymerized.

Further, in the polyester, various additives such as antioxidants, heat stabilizers, weather stabilizers, ultraviolet absorbers, organic lubricants, pigments, dyes, organic or inorganic fine particles, fillers , An antistatic agent, a nucleating agent and the like may be added to such an extent that their properties are not deteriorated.

The intrinsic viscosity of the above-mentioned polyester (25 ° C.
Measured in O-chlorophenol) is 0.4 to 1.2.
dl / g is preferable, and more preferably 0.5 to 0.8 d
Those in the range of 1 / g are suitable for practicing the present invention.

The polyester film using the above polyester is preferably biaxially oriented when the laminated film is provided. The biaxially oriented polyester film generally means an unstretched polyester sheet or film in the longitudinal direction and the width direction.
It is stretched about 5 to 5 times, and then heat-treated to complete crystal orientation, and indicates a biaxially oriented pattern by wide-angle X-ray diffraction.

The thickness of the polyester film is not particularly limited and may be appropriately selected depending on the application in which the pressure-sensitive adhesive label of the present invention is used. However, from the viewpoint of mechanical strength, handleability, etc., it is usually 1 to 500 μm. , Preferably 5
３００300 μm. Further, the obtained films can be used by being bonded by various methods.

For label applications, a white polyester film can be suitably used as a base film in addition to a transparent polyester film.
The white polyester film is not particularly limited as long as it is a white-colored polyester film, and preferably has a whiteness of 85 to 150%, more preferably 90 to 130%, and an optical density of preferably 0 to 130%. .5
To 5, more preferably 1.2 to 3. For example, when a base film having a small whiteness is used, the pattern or coloring on the opposite surface is transmitted and the appearance of the printed layer on the surface is easily impaired.On the other hand, when the optical density is small, sufficient light reflection is not obtained. It is not preferable as a white polyester film, for example, the whiteness is reduced when viewed with the naked eye, and the opposite surface is affected. The method of obtaining such optical density and whiteness is as follows.
Although not particularly limited, it can be usually obtained by adding a resin incompatible with inorganic particles or polyester. The amount to be added is not particularly limited, but in the case of inorganic particles, preferably 5 to 35% by weight, more preferably 8 to 25% by weight.
It is. On the other hand, when an incompatible resin is added, it is preferably 5 to 35% by volume, more preferably 8 to 25% by volume.
It is.

The inorganic particles are not particularly limited, but preferably have an average particle size of 0.1 to 4 μm, more preferably 0.3 to 4 μm.
1.5 μm inorganic particles and the like can be used as typical examples. Specifically, barium sulfate, calcium carbonate, calcium sulfate, titanium oxide, silica, alumina, talc, clay and the like or a mixture thereof can be used.These inorganic particles can be used in other inorganic compounds such as calcium phosphate, oxide It may be used in combination with titanium, mica, zirconia, tungsten oxide, lithium fluoride, calcium fluoride and the like. Further, when the inorganic particles having Mohs hardness of preferably 5 or less, more preferably 4 or less are used, the whiteness can be further increased.

The resin incompatible with the above polyester is not particularly limited. For example, in the case of mixing with polyethylene terephthalate or polyethylene-2,6-naphthalate, acrylic resin, polyethylene, polypropylene, modified olefin resin , Polybutylene terephthalate resin, phenoxy resin, polyphenylene oxide, and the like may be used, and may be used in combination with the above-described inorganic particles. For example, in particular, a white polyester film in which a resin incompatible with an inorganic particle or polyester is mixed and biaxially stretched to have a cavity inside and a specific gravity of 0.5 to 1.3 at the same time has a printing property. It is preferably used because it can be improved well.

The resin which is a constituent component of the laminated film according to the present invention includes, for example, acrylic resin, polyester resin,
At least one selected from urethane resin, polyolefin resin, polycarbonate resin, alkyd resin, epoxy resin, urea resin, phenol resin, vinyl chloride resin, vinyl acetate resin, fluororesin, silicone resin, rubber resin, wax resin, and the like. Can be used.

Among them, acrylic resin, polyester resin, and urethane resin are preferably used from the viewpoint of adhesiveness to a polyester film and adhesiveness to a printing layer composed of various inks, and two different resins, for example, acrylic resin It is more preferable to use a combination of a polyester resin and a polyester resin, an acrylic resin and a urethane resin, or a combination of a polyester resin and a urethane resin, since both the properties can be exhibited and the adhesiveness can be improved.

In the pressure-sensitive adhesive label of the present invention, the acrylic resin used as a constituent component of the laminated film may be, for example, an alkyl acrylate or an alkyl methacrylate (the alkyl group may be a methyl group or an ethyl group). , N-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group,
2-ethylhexyl group, lauryl group, stearyl group, cyclohexyl group, phenyl group, benzyl group, phenylethyl group, etc.), 2-hydroxyethyl acrylate,
Hydroxy-containing monomers such as -hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, acrylamide, methacrylamide, N-methylacrylamide, N
Amide group-containing monomers such as -methylmethacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, N, N-dimethylolacrylamide, N-methoxymethylacrylamide, N-methoxymethylmethacrylamide, and N-phenylacrylamide;
N, N-diethylaminoethyl acrylate, N, N-
Amino group-containing monomers such as diethylaminoethyl methacrylate, epoxy group-containing monomers such as glycidyl acrylate and glycidyl methacrylate, and carboxyl groups or salts thereof such as acrylic acid, methacrylic acid and salts thereof (lithium salt, sodium salt, potassium salt, etc.) It is possible to use a contained monomer and the like,
These are copolymerized using one kind or two or more kinds.
Further, they can be used in combination with other types of monomers.

Other types of monomers include, for example, epoxy group-containing monomers such as allyl glycidyl ether and sulfones such as styrene sulfonic acid, vinyl sulfonic acid and salts thereof (lithium salt, sodium salt, potassium salt, ammonium salt and the like). Monomers containing acid groups or salts thereof, crotonic acid, itaconic acid, maleic acid, fumaric acid and salts thereof (lithium salts, sodium salts,
Monomers containing a carboxyl group or a salt thereof, such as potassium salts and ammonium salts), maleic anhydride,
Monomers containing acid anhydrides such as itaconic anhydride, vinyl isocyanate, allyl isocyanate, styrene, vinyl methyl ether, vinyl ethyl ether, vinyl trisalkoxysilane, alkyl maleic acid monoester, alkyl fumaric acid monoester, acrylonitrile, methacryloyl Nitrile, alkyl itaconic acid monoester, vinylidene chloride, vinyl acetate, vinyl chloride, and the like can be used.

As the acrylic resin that can be used in the present invention, a modified acrylic copolymer, for example, a block copolymer or a graft copolymer modified with polyester, urethane, epoxy or the like can also be used. .

The glass transition point (Tg) of the acrylic resin used in the present invention is not particularly limited, but is preferably 0 to 90 ° C., more preferably 10 to 80 ° C.
° C. When an acrylic resin having a low Tg is used, the adhesiveness under high temperature and high humidity tends to be inferior. On the contrary, when it is too high, a crack may be generated at the time of stretching.
The molecular weight of the acrylic resin is preferably 100,000 or more, and more preferably 300,000 or more, from the viewpoint of adhesiveness.

Preferred acrylic resins used in the present invention include copolymers selected from methyl methacrylate, ethyl acrylate, n-butyl acrylate, 2-hydroxyethyl acrylate, acrylamide, N-methylol acrylamide, glycidyl methacrylate and acrylic acid. It is.

In producing the polyester film provided with the laminated film according to the present invention, a method of applying a water-based resin coating solution to the polyester film before the completion of the crystal orientation, stretching and heat-treating to complete the crystal orientation. However, it is particularly preferable because heat treatment at a high temperature is possible and a more uniform and thin laminated film can be obtained. In the case of forming a laminated film by the above method, an acrylic resin which is soluble, emulsified, or suspended in water is preferable in terms of environmental pollution and explosion-proof properties. Such an aqueous acrylic resin may be copolymerized with a monomer having a hydrophilic group (such as acrylic acid, methacrylic acid, acrylamide, vinyl sulfonic acid, or a salt thereof), emulsion-polymerized using a reactive emulsifier or a surfactant, and suspended. It can be prepared by a method such as turbid polymerization or soap-free polymerization.

In the pressure-sensitive adhesive label of the present invention, the polyester resin used as a component of the laminated film has an ester bond in a main chain or a side chain, and is obtained by polycondensation from a dicarboxylic acid and a diol.

As the carboxylic acid component constituting the polyester resin, aromatic, aliphatic and alicyclic dicarboxylic acids and trivalent or higher polycarboxylic acids can be used. As aromatic dicarboxylic acids, terephthalic acid, isophthalic acid, orthophthalic acid, phthalic acid, 2,5-dimethylterephthalic acid,
1,4-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,2-bisphenoxyethane-p, p'-dicarboxylic acid, phenylindanedicarboxylic acid, and the like can be used. These aromatic dicarboxylic acids are preferably 30 mol% or more of all dicarboxylic acid components in view of strength and heat resistance of the laminated film.
It is more preferable to use 35 mol% or more, most preferably 40 mol% or more. Aliphatic and alicyclic dicarboxylic acids include succinic acid, adipic acid, sebacic acid, azelaic acid, dodecandionic acid, dimer acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 4-cyclohexanedicarboxylic acid and the like, and their ester-forming derivatives can be used.

As the glycol component of the polyester resin, ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-propanediol, 1,3
-Butanediol, 1,4-butanediol, 1,5-
Pentanediol, 1,6-hexanediol, 1,7
-Heptanediol, 1,8-octanediol, 1,
9-nonanediol, 1,10-decanediol, 2,
4-dimethyl-2-ethylhexane-1,3-diol, neopentyl glycol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 3 -Methyl-1,5
-Pentanediol, 2,2,4-trimethyl-1,6
-Hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-
Cyclohexanedimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 4,4′-thiodiphenol, bisphenol A, 4,4′-methylenediphenol, 4,4 ′-(2 -Norbornylidene)
Diphenol, 4,4′-dihydroxybiphenol,
o-, m-, and p-dihydroxybenzene, 4,
4′-isopropylidenephenol, 4,4′-isopropylidenebindiol, cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,4-diol and the like can be used.

When the polyester resin is used as a coating liquid containing an aqueous resin, a compound containing a sulfonate group or a carboxylic acid group may be used to improve the adhesion of the polyester resin or to make the polyester resin water-soluble. It is preferable to copolymerize a compound containing an acid base.

Examples of the compound containing a carboxylate group include trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, 4-methylcyclohexene-1,2,3-tricarboxylic acid, trimesic acid, ,
2,3,4-butanetetracarboxylic acid, 1,2,3,4
-Pentanetetracarboxylic acid, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, 5- (2,5-dioxotetrahydrofurfuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid, 5- (2,5-dioxotetrahydrofurfuryl) -3-cyclohexene-
1,2-dicarboxylic acid, cyclopentanetetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid,
1,2,5,6-naphthalenetetracarboxylic acid, ethylene glycol bistrimellitate, 2,2 ', 3,3'
-Diphenyltetracarboxylic acid, thiophene-2,3
4,5-Tetracarboxylic acid, ethylenetetracarboxylic acid and the like, or alkali metal salts, alkaline earth metal salts and ammonium salts thereof can be used, but are not limited thereto.

Examples of the compound containing a sulfonate group include sulfoterephthalic acid, 5-sulfoisophthalic acid,
4-sulfoisophthalic acid, 4-sulfonaphthalene-2,
7-dicarboxylic acid, sulfo-p-xylylene glycol, 2-sulfo-1,4-bis (hydroxyethoxy)
Benzene or the like, or an alkali metal salt, an alkaline earth metal salt, or an ammonium salt thereof can be used, but is not limited thereto.

In the present invention, as the polyester resin that can be used, a modified polyester copolymer, for example, a block copolymer or a graft copolymer modified with acryl, urethane, epoxy or the like may be used. it can.

Among such polyester resins, terephthalic acid, isophthalic acid, sebacic acid, 5-
Sodium sulfoisophthalic acid, trimellitic acid, pyromellitic acid, 5- (2,5-dioxotetrahydrofurfuryl) -3-methyl-3-cyclohexene-1,2-
Dicarboxylic acid, ethylene glycol as a glycol component, diethylene glycol, 1,4-butanediol,
A copolymer selected from neopentyl glycol is preferably used.

The polyester resin used for the laminated film according to the pressure-sensitive adhesive label of the present invention can be produced by the following production method. For example, a polyester resin composed of terephthalic acid, isophthalic acid, 5-sodium sulfoisophthalic acid as a dicarboxylic acid component and ethylene glycol and neopentyl glycol as a glycol component is described. Terephthalic acid, isophthalic acid, 5-sodium sulfoisophthalic acid and ethylene Glycol, neopentyl glycol or direct esterification reaction,
It is produced by a first step of transesterifying terephthalic acid, isophthalic acid, 5-sodium sulfoisophthalic acid, ethylene glycol, and neopentyl glycol, and a second step of subjecting the reaction product of the first step to a polycondensation reaction. It can be manufactured by a method or the like.

At this time, as a reaction catalyst, for example, an alkali metal, an alkaline earth metal, manganese, cobalt, zinc, antimony, germanium, a titanium compound and the like can be used.

As a method for obtaining a polyester resin having a large number of carboxylic acids at terminals and / or side chains,
JP-A-54-46294, JP-A-60-2090
No. 73, JP-A-62-240318, JP-A-53-26828, JP-A-53-26829, JP-A-53-98336, JP-A-56-11
No. 6,718, JP-A-61-124684, JP-A-62-240318, etc. can be produced with a resin obtained by copolymerizing a trivalent or higher polycarboxylic acid. It may be a method.

The intrinsic viscosity of the polyester resin used in the laminated film according to the present invention is not particularly limited, but is preferably 0.3 dl / g or more, more preferably 0.35 dl / g, from the viewpoint of adhesiveness. Above, most preferably, it is 0.4 dl / g or more. The glass transition point (hereinafter referred to as Tg) of the aqueous polyester resin is 0
To 90 ° C., more preferably 10 to 90 ° C.
What is 80 degreeC is good. If the Tg is less than 0 ° C., the moisture-resistant adhesiveness is inferior. If the Tg exceeds 90 ° C., on the contrary, the film-forming property of the resin is inferior. Further, the acid value of the aqueous polyester resin is preferably 20 mgKOH / g or more,
More preferably, 30 mgKOH / g or more is preferably used from the viewpoint of adhesiveness, particularly moisture resistance adhesiveness.

In the laminated film according to the present invention, in particular, as the resin, two kinds of polyester resins having different Tg, and the Tg of the polyester resin having a high Tg is 6%.
It has been found that by setting the Tg of the polyester resin having a low Tg of 0 ° C. or higher and 110 ° C. or lower and lower than 60 ° C., it is possible to obtain an extremely good adhesiveness with a printing layer.

At this time, if the polyester resin used satisfies the above-mentioned Tg, the same copolymerization component such as the above-mentioned dicarboxylic acid component and diol component constituting the two different types of polyester resins is used. be able to.

According to the findings of the present inventors, the Tg of a polyester resin having a high Tg in terms of adhesiveness under high temperature and high humidity.
Is preferably 65 ° C. or more and 100 ° C. or less,
More preferably, the temperature is 70 ° C. or more and 90 ° C. or less. Further, the Tg of the polyester resin having a low Tg is preferably -10 ° C or more and 50 ° C or less, more preferably 0 ° C or more and 40 ° C or less, from the viewpoint of adhesion and blocking resistance under normal conditions. Something is good.

In particular, in the present invention, as the diol component of the polyester resin having a low Tg, a copolymer of 1,4-butanediol, neopentyl glycol and polyethylene glycol is preferably used.
Among them, those in which neopentyl glycol is copolymerized are particularly preferably used. As the dicarboxylic acid component, those obtained by copolymerizing sebacic acid, adipic acid, and azelaic acid are preferably used in terms of adhesiveness.

The copolymerization ratio of neopentyl glycol in the diol component is preferably 35 to 90 mol%, more preferably 40 to 70 mol%.

The copolymerization of polyethylene glycol is effective for making the polyester resin water-soluble.
Among them, those having a molecular weight of 600 to 20,000 are preferable, more preferably 1000 to 6000, and the copolymerization ratio is preferably 0.2 to 10 mol% in the diol component, more preferably 0.4 to 5 mol%. Mol%. Further, since the above-mentioned copolymerization ratio changes greatly depending on the molecular weight of polyethylene glycol even if the copolymerization ratio is the same, the copolymerization amount of polyethylene glycol is preferably 1 to 20% by weight in terms of% by weight in the polyester resin. , More preferably 2 to 15% by weight.

In the pressure-sensitive adhesive label of the present invention, the urethane resin used as a component of the laminated film is not particularly limited as long as it is a water-soluble or water-dispersible urethane resin having an anionic group. Is obtained by copolymerizing a polyol and a polyisocyanate.

As the urethane resin, a resin whose affinity for water is increased by a carboxylic acid group, a sulfonic acid group, or a sulfuric acid half ester base can be used. The content of a carboxylate group, a sulfonate group, a sulfuric acid half ester base or the like is preferably 0.5 to 15% by weight.

Examples of the polyol compound include polyethylene glycol, polypropylene glycol, polyethylene propylene glycol, polytetramethylene glycol, hexamethylene glycol, hexamethylene glycol, tetramethylene glycol, 1,5-pentanediol, diethylene glycol, and triethylene glycol. , Polycaprolactone, polyhexamethylene adipate, polytetramethylene adipate, trimethylolpropane, trimethylolethane, glycerin,
An acrylic polyol or the like can be used.

Examples of the polyisocyanate compound include tolylene diisocyanate, hexamethylene diisocyanate, phenylene diisocyanate, diphenylmethane diisocyanate, an adduct of tolylene diisocyanate and trimethylolpropane, and an adduct of hexamethylene diisocyanate and trimethylolethane. Can be.

Here, the main constituent components of the urethane resin may contain a chain extender, a crosslinking agent and the like in addition to the above-mentioned polyol compound and polyisocyanate compound.

As a chain extender or a crosslinking agent, ethylene glycol, propylene glycol, butanediol, diethylene glycol, ethylenediamine, diethylenetriamine and the like can be used.

Examples of the urethane resin having an anionic group include a method using a compound having an anionic group as a polyol, a polyisocyanate, a chain extender, and the like, and a method having an unreacted isocyanate group and an anionic group in a formed urethane resin. It can be produced by a method of reacting a compound, a method of reacting a group having an active hydrogen of a urethane resin with a specific compound, and the like, but is not particularly limited.

Further, a resin comprising a polyol having a molecular weight of 300 to 20,000, a polyisocyanate, a chain extender having a reactive hydrogen atom, a compound having a group which reacts with an isocyanate group, and a compound having at least one anionic group is preferable.

The anionic group in the urethane resin is preferably used as a sulfonic acid group, a carboxylic acid group or an ammonium salt, a lithium salt, a sodium salt, a potassium salt or a magnesium salt thereof, and particularly preferably,
It is a sulfonate group.

The amount of the anionic group in the polyurethane resin is preferably 0.05% by weight to 8% by weight. If the amount is less than 0.05% by weight, the water dispersibility of the urethane resin tends to deteriorate, and if it exceeds 8% by weight, the water resistance and the blocking resistance of the resin tend to deteriorate.

In the laminated film according to the present invention, the above-mentioned resin, preferably an acrylic resin, a polyester resin,
By using a melamine-based crosslinking agent and an oxazoline-based crosslinking agent in combination with a resin selected from at least one urethane resin, the adhesiveness under normal conditions is improved, and the adhesiveness under high temperature and high humidity is dramatically improved. It is found that it is improved.

The melamine cross-linking agent used in the present invention is not particularly limited, but is partially or completely reacted by reacting a lower alcohol with melamine, a methylolated melamine derivative obtained by condensing melamine and formaldehyde, or a methylolated melamine to partially or completely. Etherified compounds or mixtures thereof can be used. In addition, as the melamine-based cross-linking agent, a monomer, a condensate composed of a multimer of a dimer or more, or a mixture thereof can be used. As the lower alcohol used for the etherification, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, isobutanol and the like can be used. The functional group has an imino group, a methylol group, or an alkoxymethyl group such as a methoxymethyl group or a butoxymethyl group in one molecule, and includes an imino group-type methylated melamine resin, a methylol group-type melamine resin, and a methylol group-type. Methylated melamine resins, fully alkylated methylated melamine resins, and the like. Among them, a methylolated melamine resin is most preferable. Furthermore, in order to accelerate the thermal curing of the melamine-based crosslinking agent,
For example, an acidic catalyst such as p-toluenesulfonic acid may be used.

The oxazoline crosslinking agent used in the present invention is not particularly limited as long as the compound has an oxazoline group as a functional group in the compound, and includes at least one kind of monomer having an oxazoline group. Those comprising an oxazoline group-containing copolymer are preferred.

Examples of the oxazoline-based crosslinking agent include JP-A-2-60941, JP-A-2-99537, JP-A-2-115238, and JP-B-63-48.
The copolymer described in JP-A-884 or the derivative thereof can be used.

Specifically, the following general formula is used.

[0067]

Embedded image (Wherein R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen, halogen, alkyl, aralkyl, phenyl or substituted phenyl group, and R ₅ is a noncyclic organic group having an addition-polymerizable unsaturated bond. Can be used. A copolymer obtained by copolymerizing the addition-polymerizable oxazoline represented by the formula (1) and at least one other monomer can be used.

Examples of the addition-polymerizable oxazoline include 2-vinyl-2-oxazoline and 2-vinyl-4-methyl-2.
-Oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-
Isopropenyl-4-methyl-2-oxazoline, 2-
Isopropenyl-5-ethyl-2-oxazoline and the like can be used, and one or a mixture of two or more thereof can also be used. Among them, 2-isopropenyl-2-oxazoline is preferable because it is easily available industrially.

In the oxazoline-based crosslinking agent, at least one other monomer used for the addition-polymerizable oxazoline is not particularly limited as long as it is a monomer copolymerizable with the addition-polymerizable oxazoline.
Acrylic esters or methacrylic esters such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, and acrylic acid , Methacrylic acid, itaconic acid, unsaturated carboxylic acids such as maleic acid, acrylonitrile, unsaturated nitriles such as methacrylonitrile, acrylamide, methacrylamide, N-methylol acrylamide, unsaturated amides such as N-methylol methacrylamide, Vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; olefins such as ethylene and propylene; vinyl chloride; vinyl chloride Α-, β-unsaturated monomers such as styrene and vinyl fluoride, and α, β-unsaturated aromatic monomers such as styrene and α-methylstyrene. Mixtures of more than one species can also be used.

In order to obtain an oxazoline-based crosslinking agent using addition-polymerizable oxazoline and at least one other monomer, polymerization may be carried out by an emulsion polymerization method, a solution polymerization method, or the like.

For example, in the emulsion polymerization method, a polymerization catalyst, water,
Various methods such as a method in which a surfactant and a monomer are mixed at a time and polymerization, or a monomer dropping method, a multi-stage polymerization method, a pre-emulsion method and the like can be used. Polymerization catalysts include, for example, benzoyl peroxide, t-butyl hydroperoxide, azobisisobutyronitrile, hydrogen peroxide, potassium persulfate, ammonium persulfate, 2,2 ′
-A radical polymerization initiator such as azobis (2-amidinopropane) dihydrochloride can be used. As the surfactant, an anionic surfactant, a cationic surfactant, a nonionic surfactant, an amphoteric surfactant, a reactive surfactant, or the like can be used. The polymerization temperature is usually 0 to 100 ° C, preferably 50 to 80 ° C, and the polymerization time is usually 1 to 10 ° C.
Time.

In the solution polymerization method, usable solvents include toluene, hexane, methyl ethyl ketone, ethyl cellosolve, methyl cellosolve, ethyl acetate, isopropyl alcohol, propylene glycol monomethyl ether and the like. Can also be used. Examples of the polymerization initiator used include azobisisobutyronitrile and benzoyl peroxide. The polymerization temperature is from 20 to 200C, preferably from 40 to 120C.

In obtaining an oxazoline-based cross-linking agent using an addition-polymerizable oxazoline and another monomer, the amount of the addition-polymerizable oxazoline used is 0.5 to 8 in all monomers.
There is no particular limitation as long as it is in the range of 0% by weight or more. If the amount of the addition-polymerizable oxazoline is less than 0.5% by weight, the crosslinking effect due to the oxazoline group is small, and the adhesiveness tends to be poor. If it exceeds 80% by weight, the affinity with other resins used in combination and the crosslinking agent It tends to be poor in its own polymerizability.

The oxazoline-based crosslinking agent thus obtained is obtained, for example, in the form of an aqueous dispersion by an emulsion polymerization method and in the form of an organic solvent liquid by a solution polymerization method.
Any of these can be used as it is as a coating liquid for forming a laminated film. In addition, a solution obtained by a solution polymerization method can also be used as a pseudo-aqueous coating liquid by a method such as addition of water as long as it is an aqueous organic solvent. In particular, the resin obtained in this manner is, when used in combination with another resin, for example, an aqueous resin, from the form of the aqueous dispersion obtained by the emulsion polymerization method, the resin used in the present invention. Is preferred because the affinity of the compound becomes higher and the crosslinking effect becomes remarkably higher.

In the present invention, in addition to the above-mentioned melamine-based crosslinking agent and oxazoline-based crosslinking agent, a crosslinking agent capable of undergoing a crosslinking reaction with a functional group present in the resin, for example, a hydroxyl group, a carboxyl group, a methylol group or the like is used in combination. May be. For example, methylolated or alkylolated urea-based, acrylamide-based, polyamide-based resin, epoxy compound, isocyanate compound, aziridine compound,
Various silane coupling agents, various titanate coupling agents, and the like can be used.

In the laminated film according to the present invention, the resin, the melamine-based cross-linking agent and the oxazoline-based cross-linking agent can be used in a mixture at an arbitrary ratio. May be mixed in the following ratio.

The melamine crosslinking agent is used in an amount of 0.2 to
Addition of 20 parts by weight is preferable from the viewpoint of improving adhesion under normal conditions, more preferably 0.5 to 15 parts by weight, and most preferably 1 to 10 parts by weight. When the addition amount of the melamine-based crosslinking agent is less than 0.2 parts by weight, the effect of the addition is small, and when it exceeds 20 parts by weight, the adhesiveness tends to decrease.

The oxazoline-based crosslinking agent is used in an amount of 0.1% based on the resin.
The addition of 2 to 20 parts by weight is preferable from the viewpoint of improving the adhesion under normal conditions, more preferably 0.5 to 15 parts by weight, and most preferably 1 to 10 parts by weight. When the addition amount of the oxazoline-based crosslinking agent is less than 0.2 parts by weight, the effect of the addition is small, and when it exceeds 20 parts by weight, the adhesiveness tends to decrease.

Further, it should be particularly noted in the present invention that the weight ratio of the above-mentioned melamine-based crosslinking agent and oxazoline-based crosslinking agent ([oxazoline-based crosslinking agent] / [melamine-based crosslinking agent]), 0.1 to 0.1)
It has been found that setting to 10 has a remarkable effect on adhesiveness under high temperature and high humidity. According to the findings of the present inventors, by setting the addition weight ratio to 0.5 to 5, excellent adhesiveness particularly under high temperature and high humidity is obtained.

The laminated film according to the present invention comprises the above-mentioned resin, melamine-based cross-linking agent and oxazoline-based cross-linking agent as main constituent components. In the present invention, the main component is 70% by weight in the laminated film. It means occupying the above. In particular, in the present invention, the component ratio is preferably 80% by weight or more, more preferably 90% by weight or more.

In the laminated film, various additives such as an antioxidant, a heat stabilizer, a weather stabilizer, an ultraviolet absorber, an organic lubricant, and the like are used as long as the effects of the present invention are not impaired.
Pigments, dyes, organic or inorganic fine particles, fillers, antistatic agents, nucleating agents and the like may be blended.

In particular, those in which inorganic particles are added to the laminated film are more preferable because the lubricity and blocking resistance are improved.

In this case, as the inorganic particles to be added, silica, colloidal silica, alumina, alumina sol, kaolin, talc, mica, calcium carbonate and the like can be used. The inorganic particles used have an average particle size of 0.0
1-5 μm is preferable, and more preferably 0.05-3 μm
m, most preferably 0.08 to 2 μm, and the mixing ratio with respect to the resin in the laminated film is not particularly limited, but is preferably 0.05 to 8 parts by weight, more preferably 0.1 to 3 parts by weight in terms of solid content weight ratio. Parts by weight.

In producing the pressure-sensitive adhesive label of the present invention,
The most preferable method for providing the laminated film is a method in which the film is applied during the production process of the polyester film and stretched together with the base film. For example, the melt-extruded polyester film before crystal orientation is stretched about 2.5 to 5 times in the longitudinal direction, and a coating liquid is continuously applied to the uniaxially stretched film. The applied film is dried while passing through a stepwise heated zone, and is dried in the width direction.
It is stretched about 5 to 5 times. Furthermore, 150 to 25 continuously
It can be obtained by a method (in-line coating method) of being guided to a heating zone at 0 ° C. and completing the crystal orientation. The coating solution used in this case is preferably an aqueous solution in view of environmental pollution and explosion-proof properties.

In the present invention, before applying the coating liquid,
The surface of the base film (in the case of the above example, the uniaxially stretched film) is subjected to a corona discharge treatment or the like, and the wetting tension of the surface is preferably 47 mN / m or more, more preferably 50 mN / m or more.
mN / m or more can be preferably used because the adhesiveness of the laminated film to the base film can be improved.

Although the thickness of the laminated film is not particularly limited, it is usually preferably in the range of 0.01 to 5 μm, more preferably 0.02 to 2 μm, and most preferably 0.05 μm to 0.2 μm.
5 μm. If the thickness of the laminated film is too small, poor adhesion may occur.

As a method of coating on the substrate film, various coating methods, for example, a reverse coating method, a gravure coating method, a rod coating method, a bar coating method, a Meyer bar coating method, a die coating method, a spray coating method and the like are used. be able to.

The pressure-sensitive adhesive layer according to the present invention is not particularly limited as long as it has a pressure-sensitive adhesive property, and its composition is not particularly limited, but is roughly classified into rubber-based, acrylic-based, vinyl-based, and silicone-based. Is done. Among them, a rubber type and an acrylic type are preferably used for the adhesive label.

The rubber-based pressure-sensitive adhesive generally comprises a rubber elastomer, a softener, and a tackifier as main components, and further includes a filler and an antioxidant as needed.

As rubber elastomers, natural rubber, styrene-butadiene rubber (SBR), butyl rubber, polyisobutylene, butadiene, styrene-isoprene block copolymer (SIS), styrene-butadiene block copolymer (SBS), recycled rubber, etc. Can be used.

As the tackifier resin, rosin and rosin derivatives, gum rosin, terpene resin, petroleum resin, oil-soluble phenol resin and the like can be used. In addition, polybutene, Liquid rubber, phthalic acid plasticizer, mineral oil and the like can be added. Further, as the softener, mineral oil, liquid polybutene, liquid polyacrylate, lanolin and the like can be used.

[0092] The filler added as needed includes
Antioxidants such as zinc oxide, aluminum hydrate, titanium oxide, calcium carbonate, clay, and pigments, and antioxidants for rubber, dithiocarbamates, metal chelates, and the like can be used.

On the other hand, acrylic pressure-sensitive adhesives are mainly composed of acrylates such as butyl acrylate and 2-ethylhexyl acrylate, and these resins are too soft. It can be used after being copolymerized with ethylene-acrylic acid, methyl acrylate, alkyl methacrylate and the like. Other additives include tackifiers, softeners, and fillers used in the above-mentioned rubber-based pressure-sensitive adhesive.

In the case of an acrylic pressure-sensitive adhesive, it is also possible to introduce a functional monomer containing a carboxylic acid, a hydroxyl group, an acid amide or the like to improve heat resistance and oil resistance, and to form a cross-linkable pressure-sensitive adhesive. As a crosslinking agent for performing crosslinking, diisocyanate, melamine, or the like can be used.

As the silicone pressure-sensitive adhesive, a compound mainly composed of a mixture of a rubbery siloxane and a resinous siloxane polymer can be used, and it can be adhered to Teflon or silicone rubber which is difficult to adhere. have.

As the vinyl-based pressure-sensitive adhesive, those containing a vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polyvinyl ether or the like as a main component can be used.

[0097] As a method of applying the adhesive, a direct method in which an adhesive is directly applied to a surface substrate and bonded to a release paper,
An indirect method or the like can be used in which an adhesive is applied to the silicone-coated surface of the release paper and the adhesive is bonded to the surface substrate.

The method of applying the pressure-sensitive adhesive is not particularly limited, and a doctor coater, a comma doctor, a kiss roll coater, a reverse roll coater, or the like can be used.

The print layer according to the present invention is not particularly limited as long as it has a display function. In the present invention, the printing layer is provided on the laminated film, the printing method is not particularly limited, generally, offset printing,
Methods such as screen printing and gravure printing can be used. In addition, the printing ink used at that time is also selected according to the printing method, and is not particularly limited, and an ultraviolet curable ink, an oxidation polymerization ink, an electron beam curable ink, a flexographic ink, a screen ink, or the like can be used. .

Next, the method for producing the pressure-sensitive adhesive label of the present invention will be described with reference to polyethylene terephthalate (hereinafter referred to as “PET”).
Will be described as an example, but the present invention is not limited to this.

The pressure-sensitive adhesive label of the present invention, which has excellent adhesiveness to the above-mentioned printing layer and also has excellent adhesiveness even after being treated under high temperature and high humidity, is a pressure-sensitive adhesive layer, a polyester film, and the above-mentioned resin, melamine. It can be manufactured by laminating a laminated film mainly comprising a system crosslinking agent and an oxazoline crosslinking agent in this order, and providing a printing layer on at least a part of the laminated film.

More specifically, for example, the limiting viscosity is 0.5
After vacuum drying of ~ 0.8 dl / g PET pellets,
It is supplied to an extruder, melted at 260 to 300 ° C., extruded from a T-shaped die into a sheet, wound around a mirror casting drum having a surface temperature of 10 to 60 ° C. using an electrostatic application casting method, and cooled and solidified. An unstretched PET film was prepared. This unstretched film is stretched 2.5 to 5 times in the longitudinal direction (the direction of film movement) between rolls heated to 70 to 120 ° C. At least one surface of the film is subjected to a corona discharge treatment, and the wetting tension of the surface is set to 47 mN.
/ M or more, and the coating liquid for forming a laminated film of the present invention was applied to the treated surface. The coated film is gripped with a clip, guided to a hot air zone heated to 70 to 150 ° C., dried, stretched 2.5 to 5 times in the width direction, and then stretched 160 times.
It was led to a heat treatment zone of ２５０250 ° C. and heat-treated for 1 to 30 seconds to complete the crystal orientation. During this heat treatment step, a 3 to 12% relaxation treatment may be performed in the width direction or the longitudinal direction as necessary. The biaxial stretching may be any of longitudinal and transverse sequential stretching or simultaneous biaxial stretching, and may be re-stretched in any of the longitudinal and transverse directions after the longitudinal and transverse stretching. Also,
The thickness of the polyester film is not particularly limited, but is preferably 5 to 300 μm. The coating liquid used in this case is preferably water-based in view of environmental pollution and explosion-proof properties.

In the above example, the base film on which the laminated film is provided may contain at least one selected from melamine-based crosslinking agents, oxazoline-based crosslinking agents, and reaction products thereof. in this case,
There are effects such as improvement in the adhesion between the laminated film and the base film, and improvement in the lubricity of the laminated polyester film. When a melamine-based cross-linking agent, an oxazoline-based cross-linking agent, or a reaction product thereof is contained, the total amount of one or more of them may be 5 ppm or more and 20 or more.
It is preferable that the content is less than the weight% in terms of adhesiveness and lubricity. Of course, the melamine-based crosslinking agent, the oxazoline-based crosslinking agent, or the reaction product thereof may be a laminated film forming composition (including a recycled pellet of the laminated polyester film of the present invention) provided on the base film. .

The thus obtained laminated polyester film is slit into a width suitable for the pressure-sensitive adhesive application step, and the surface on which the laminated film is not provided (however, when the laminated film is provided on both surfaces, On any surface), an adhesive layer made of the above-mentioned adhesive is provided, and slit to a predetermined width. Further, by performing the above-described printing on the surface on which the adhesive layer is not provided, that is, on the laminated film, an adhesive label having various display functions can be obtained.

[0105]

[Method for measuring characteristics and method for evaluating effects] The method for measuring characteristics and the method for evaluating effects in the present invention are as follows.

(1) Thickness of Laminated Film The thickness was determined from a photograph obtained by observing a cross section of an adhesive label formed of a laminated polyester film provided with a laminated film using a transmission electron microscope HU-12 manufactured by Hitachi, Ltd. The thickness was an average value of 30 pieces in the measurement visual field.

(2) Adhesiveness-1 100 crosscuts of 1 mm ² were put on the printing layer of the pressure-sensitive adhesive label of the present invention, and a cellophane tape manufactured by Nichiban Co., Ltd. was adhered thereon, and a rubber roller was used. Load 19.
After reciprocating three times at 6N and pressing, peeling was performed in the direction of 90 °, and a four-level evaluation was made based on the number of remaining print layers (◎: 10
0, ○: 80 to 99, Δ: 50 to 79, ×: 0 to 49)
did. (A) and (B) were evaluated as having good adhesiveness.

(3) Adhesion-2 The adhesive label of the present invention was subjected to a high-temperature and high-humidity treatment (95 ° C., 1
For a period of time in hot water). Immediately after the treatment, the adhered moisture was wiped off, and three minutes later, the same evaluation as in the above (2) was performed.

(4) Adhesiveness-3 The adhesive label of the present invention was subjected to a high-temperature and high-humidity treatment (80 ° C., 3
For a period of time in hot water). Immediately after the treatment, the adhered moisture was wiped off, and three minutes later, the same evaluation as in the above (2) was performed.

(5) Glass transition point (Tg) A robot DSC (differential scanning calorimeter) RDC220 manufactured by Seiko Denshi Kogyo Co., Ltd.
The measurement was performed with a 5200 disk station connected. D
The measurement conditions of SC are as follows. That is, the sample 10 mg
Is adjusted to an aluminum pan, then set in a DSC device (reference: aluminum pan of the same type without a sample), heated at 300 ° C. for 5 minutes, and then quenched in liquid nitrogen. This sample was heated at 10 ° C /
And the DSC chart Tg is detected.

[0111]

Next, the present invention will be described with reference to examples, but is not necessarily limited thereto.

Example 1 PET pellets containing 0.015% by weight of colloidal silica having an average particle diameter of 0.4 μm and 0.005% by weight of colloidal silica having an average particle diameter of 1.5 μm (intrinsic viscosity: 0.63 dl / g) ) Is sufficiently dried in a vacuum, fed to an extruder, melted at 285 ° C., extruded into a sheet shape from a T-shaped die, and subjected to a surface temperature of 20 using an electrostatic application casting method.
It was wrapped around a mirror-surfaced casting drum at ℃ to be cooled and solidified. This unstretched film was heated to 95 ° C. and stretched 3.5 times in the longitudinal direction to obtain a uniaxially stretched film. The film was subjected to a corona discharge treatment in air, the wet tension of the substrate film was set to 52 mN / m, and the following coating liquid for forming a laminated film was applied to the treated surface. While holding the applied uniaxially stretched film with a clip, it is led to a preheating zone,
After that, the film was continuously stretched 3.5 times in the width direction in a heating zone at 125 ° C., and further subjected to a heat treatment in a heating zone at 225 ° C. to obtain a laminated PET film in which crystal orientation was completed. At this time, the base PET film thickness is 50 μm,
The thickness of the laminated film was 0.15 μm.

The obtained laminated polyester film is slit into a predetermined width, and an adhesive made of an ethylene-vinyl acetate copolymer resin is applied to the surface on which the laminated film is not provided by a reverse roll coating method and dried. A 5 μm pressure-sensitive adhesive layer was provided. Thereafter, dry lamination was performed using paper laminated with polyethylene coated with thermosetting silicone as release paper.

Further, on the surface on which the pressure-sensitive adhesive layer is not provided, that is, on the laminated film, an ultraviolet curable ink (FLASH D
After offset printing of RY (FDS Ink TJ) (manufactured by Toyo Ink Mfg. Co., Ltd.), the irradiation distance (the distance between the lamp and the ink surface) is 9c using an ultraviolet lamp having an irradiation intensity of 80 W / cm.
m for 5 seconds to cure the UV curable ink,
A printing layer having a thickness of 1.5 μm was provided to obtain an adhesive label having a display function. Table 1 shows the results.

“Laminated film forming coating liquid” Acrylic resin: Methyl methacrylate 65% by weight Ethyl acrylate 32% by weight Acrylic acid 2% by weight N-methylolacrylamide 1% by weight An acrylic resin copolymer emulsion copolymerized with the above composition.

Melamine-based cross-linking agent: methylolated melamine was mixed with a mixed solvent of isopropyl alcohol and water (10 /
90 (weight ratio)).

Oxazoline-based crosslinking agent: Methyl methacrylate 50% by weight Ethyl acrylate 25% by weight Styrene 5% by weight 20% by weight of 2-isopropenyl-2-oxazoline The oxazoline group-containing resin composition copolymerized with the above composition is mixed with propylene glycol monomethyl A coating solution diluted in a mixed solvent of ether and water (20/80 (weight ratio)).

A coating liquid for forming a laminated film was prepared by adding 2 parts by weight of a melamine-based crosslinking agent and 5 parts by weight of an oxazoline-based crosslinking agent to 100 parts by weight of the above acrylic resin.

Example 2 An adhesive label was prepared in the same manner as in Example 1 except that the following urethane resin was used as the resin for forming a laminated film in Example 1, and 2 parts by weight of an oxazoline-based crosslinking agent was used. Obtained.
Table 1 shows the results.

Urethane resin: 192 parts by weight of polyether containing sodium sulfonate obtained by sulfonating polyether of ethylene oxide (sulfonic acid group content: 8% by weight), 1013 parts by weight of polytetramethylene adipate,
248 parts by weight of polypropylene oxide polyether were mixed, dehydrated at 100 ° C. under reduced pressure, the mixture was heated to 70 ° C., and a mixture of 178 parts by weight of isophorone diisocyanate and 244 parts by weight of hexamethylene-1,6-diisocyanate was added, The product mixture was further stirred at 80-90 ° C. until the isocyanate content was 5.6% by weight. The obtained prepolymer was cooled to 60 ° C., and bisketimine 173 obtained from 56 parts by weight of biuret polyisocyanate obtained from 3 moles of hexamethylene diisocyanate and 1 mole of water, isophoronediamine and acetone was used.
Parts by weight. Then, hydrazine hydrate 1
An aqueous solution at 50 ° C. in which 5 parts by weight was dissolved was added to this mixture with stirring to obtain a urethane resin aqueous dispersion.

Example 3 An adhesive label was obtained in the same manner as in Example 1 except that a mixture of the following two polyester resins was used as the resin in the coating liquid for forming a laminated film of Example 1. Table 1 shows the results.

Polyester resin-1: Acid component Terephthalic acid 45 mol% Isophthalic acid 32 mol% Sebacic acid 20 mol% 5-Sodium sulfoisophthalic acid 3 mol% Diol component Ethylene glycol 55 mol% Neopentyl glycol 44 mol% Polyethylene Glycol (molecular weight 4000) 1 mol% A polyester resin comprising the above-mentioned acid component and diol component was mixed with a mixture of t-butyl cellosolve and water (10/90
(Weight ratio)).

Polyester resin-2: Acid component 88 mol% terephthalic acid 12 mol% 5-sodium sulfoisophthalic acid 12 mol% diol component Ethylene glycol 99 mol% 1 mol% diethylene glycol 1 mol% Water solubility of polyester resin comprising the above acid component and diol component Coating liquid.

A total of 100 parts by weight of the above-mentioned polyester resin-1 and 50 parts by weight of the polyester resin-1 was added with 2 parts by weight of a melamine crosslinking agent and 5 parts by weight of an oxazoline crosslinking agent. Was used as a coating liquid for forming a laminated film.

Example 4 Adhesion was carried out in the same manner as in Example 3, except that 5 parts by weight of a melamine crosslinking agent and 5 parts by weight of an oxazoline crosslinking agent were added to the coating liquid for forming a laminated film of Example 3. Got the label. Table 1 shows the results.

Example 5 Adhesion was carried out in the same manner as in Example 3, except that 1 part by weight of a melamine-based crosslinking agent and 20 parts by weight of an oxazoline-based crosslinking agent were used in the coating liquid for forming a laminated film of Example 3. Got the label. Table 1 shows the results.

Example 6 In the coating solution for forming a laminated film of Example 3, 10
A pressure-sensitive adhesive label was obtained in the same manner as in Example 3, except that 2 parts by weight of the oxazoline-based crosslinking agent was added and 2 parts by weight of the oxazoline-based crosslinking agent were used. Table 1 shows the results.

Example 7 An adhesive label was obtained in the same manner as in Example 3, except that Toka 161 black manufactured by Toka Pigment Co., Ltd. was used as the ultraviolet-curable ink used as the printing layer. Table 1 shows the results.

Example 8 In Example 3, the polyester film was changed from polyethylene terephthalate film to polyethylene-2,6-
A laminated PEN film was obtained in the same manner as in Example 3, except that the film was changed to a naphthalate (hereinafter abbreviated as "PEN") film. Table 1 shows the results.

Example 9 A polybutylene terephthalate was previously prepared by adding polytetramethylene glycol during the polymerization of polybutylene terephthalate so that the weight ratio of polybutylene terephthalate to polytetramethylene glycol (molecular weight: 4000) would be 1: 1. 1% by weight of butylene terephthalate-polytetramethylene glycol copolymer and polymethylpentene (TPX, DX820, manufactured by Mitsui Petrochemical Co., Ltd.)
Wt% PET pellet (intrinsic viscosity 0.63d
1 / g) is sufficiently dried in vacuum, and then supplied to an extruder A heated to 285 ° C. In addition, the same PET pellets as described above are sufficiently dried in vacuum, and then supplied to an extruder B heated to 285 ° C. The polymers extruded from the extruders A and B are laminated by coextrusion so as to form a three-layer structure of B / A / B, extruded into a sheet shape from a T-shaped die, and the surface temperature is determined by using an electrostatic application casting method. It was wound around a mirror casting drum at 20 ° C. and solidified by cooling.
This unstretched film was heated to 95 ° C. and stretched three times in the longitudinal direction to obtain a uniaxially stretched film. The film was subjected to a corona discharge treatment in air, the wet tension of the substrate film was set to 52 mN / m, and the same coating liquid for forming a laminated film as in Example 3 was applied to the treated surface. The coated uniaxially stretched film is guided to a preheating zone while being gripped with a clip, dried at 110 ° C., and then continuously stretched 3.2 times in the width direction in a 125 ° C. heating zone, and further in a 225 ° C. heating zone. Heat treatment was performed to obtain a white laminated PET film provided with a laminated film whose crystal orientation was completed. At this time, the thickness of the base white PET film was 50 μm (the thickness ratio was B / A / B = 5/90 /
5) The optical density was 1.2, the whiteness was 70%, and the thickness of the laminated film was 0.15 μm.

The obtained white laminated PET film was provided with an adhesive layer, a release paper and a printing layer in the same manner as in Example 3 to obtain an adhesive label. Table 1 shows the results.

Example 10 PE containing 14% by weight of titanium dioxide having an average particle size of 0.2 μm and 0.5% by weight of silica having an average particle size of 1 μm
T pellets (intrinsic viscosity: 0.63 dl / g) are sufficiently dried in vacuum, then supplied to an extruder and melted at 285 ° C.
The sheet was extruded into a sheet shape from a letter-shaped die, wound around a mirror-surface casting drum having a surface temperature of 20 ° C. using an electrostatic application casting method, and cooled and solidified. This unstretched film is
The film was heated to 5 ° C. and stretched 3.2 times in the longitudinal direction to obtain a uniaxially stretched film. This film is subjected to a corona discharge treatment in the air, and the wetting tension of the base film is set to 52 mN / m.
The same coating liquid for forming a laminated film as in Example 8 was applied to the treated surface. The coated uniaxially stretched film is guided to a preheating zone while being gripped with a clip, dried at 110 ° C., and then continuously stretched 3.2 times in the width direction in a 125 ° C. heating zone, and further in a 225 ° C. heating zone. Heat treatment was performed to obtain a white laminated PET film provided with a laminated film whose crystal orientation was completed. At this time, the thickness of the base white PET film was 50
μm, the optical density was 1.6, the whiteness was 88%, and the thickness of the laminated film was 0.15 μm.

The obtained white laminated PET film was provided with an adhesive layer, release paper and a printing layer in the same manner as in Example 3 to obtain an adhesive label. Table 1 shows the results.

Example 11 The same procedure as in Example 1 was carried out except that the laminated PET film obtained in Example 1 was pulverized and pelletized, and 20% by weight of polyethylene terephthalate was added thereto and melt-extruded. To obtain an adhesive label. Table 1 shows the results.

Comparative Example 1 In the same manner as in Example 1 except that the following polyester resin was used as the resin in the coating liquid for forming a laminated film of Example 1 and the melamine-based crosslinking agent and the oxazoline-based crosslinking agent were not used. To obtain an adhesive label. Table 1 shows the results.

Polyester resin: acid component terephthalic acid 45 mol% isophthalic acid 32 mol% sebacic acid 20 mol% 5-sodium sulfoisophthalic acid 3 mol% diol component ethylene glycol 55 mol% neopentyl glycol 44 mol% polyethylene glycol ( 1 mol% The polyester resin comprising the acid component and the diol component was mixed with a mixed solution of t-butyl cellosolve and water (10/90).
(Weight ratio)) was used as a polyester resin aqueous dispersion.

Comparative Example 2 Adhesion was carried out in the same manner as in Comparative Example 1 except that 5 parts by weight of a melamine-based crosslinking agent was added to the coating liquid for forming a laminated film of Comparative Example 1 and no oxazoline-based crosslinking agent was added. Got the label. Table 1 shows the results.

Comparative Example 3 An adhesive was prepared in the same manner as in Comparative Example 1, except that 5 parts by weight of an oxazoline-based crosslinking agent was added to the coating liquid for forming a laminated film of Comparative Example 1 and no melamine-based crosslinking agent was added. Got the label. Table 1 shows the results.

Comparative Example 4 In the coating liquid for forming a laminated film of Comparative Example 1, Takeda Pharmaceutical Company Limited was used as an isocyanate-based crosslinking agent instead of a melamine-based crosslinking agent.
Except that 10 parts by weight of "Prominate" XC-915 manufactured by Co., Ltd. were added and used without adding an oxazoline-based crosslinking agent.
An adhesive label was obtained in the same manner as in Comparative Example 1. Table 1 shows the results.

Comparative Example 5 In the coating liquid for forming a laminated film of Comparative Example 1, 2 parts by weight of a melamine-based cross-linking agent was added, and an epoxy-based cross-linking agent was used instead of the oxazoline-based cross-linking agent. An adhesive label was obtained in the same manner as in Comparative Example 1, except that 10 parts by weight of Agent CR-5L was used. Table 1 shows the results.

[0141]

[Table 1]

[0142]

According to the present invention, there is provided a pressure-sensitive adhesive label exhibiting excellent adhesiveness to a printing layer provided on the pressure-sensitive adhesive label and exhibiting excellent adhesiveness even after treatment under high temperature and high humidity. can do.

Claims (7)

[Claims] An adhesive layer is provided on one surface of a polyester film having a laminated film provided on at least one surface,
An adhesive label comprising a printed layer provided on a laminated film on the other side, wherein the laminated film is mainly composed of a resin, a melamine-based crosslinking agent and an oxazoline-based crosslinking agent. 2. The pressure-sensitive adhesive label according to claim 1, wherein the resin is at least one selected from an acrylic resin, a polyester resin, and a urethane resin. 3. The laminated film according to claim 1, wherein the melamine-based crosslinking agent is 0.2 to 20 parts by weight, the oxazoline-based crosslinking agent is 0.2 to 20 parts by weight, and the crosslinking agent is based on the resin. 3. The composition according to claim 1, wherein the weight ratio ([oxazoline-based crosslinking agent] / [melamine-based crosslinking agent]) is in the range of 0.1 to 10. Sticky label. 4. The resin comprises two kinds of polyester resins having different glass transition points, and the polyester resin having a high glass transition point has a glass transition point of 60 ° C. or higher.
The pressure-sensitive adhesive label according to any one of claims 1 to 3, wherein the polyester resin having a glass transition point of not higher than 10 ° C has a glass transition point of lower than 60 ° C. 5. The pressure-sensitive adhesive label according to claim 1, wherein the polyester film is a polyethylene terephthalate film, a polypropylene terephthalate film, or a polyethylene-2,6-naphthalate film. 6. The laminated film is formed by applying the coating liquid for forming a laminated film on at least one side of a polyester film before completion of crystal orientation, and then stretching and heat-treating in at least one direction. The pressure-sensitive adhesive label according to any one of claims 1 to 5. 7. A polyester film comprising a composition containing a total of at least 5 ppm and less than 20% by weight of at least one selected from a melamine-based crosslinking agent, an oxazoline-based crosslinking agent, and a reaction product thereof. The pressure-sensitive adhesive label according to any one of claims 1 to 6, wherein