JP2008100711A - Glass bottle with heat-sensitive label - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glass bottle extremely suitable for recycling which is stuck with a heat-sensitive label having excellent adhesiveness and easy releasabilty, and makes both high decorativeness and high recycling performance compatible since it is applied with a resin coating. <P>SOLUTION: The glass bottle with a heat-sensitive label is characterized in that the outer face of the glass bottle having a resin coating layer with a thickness of 5-20 μm comprising resin with a polar group is fitted with the heat-sensitive label with a heat-sensitive adhesive layer comprising a 20-70 wt.% ethylene-vinyl acetate copolymer, a 20-50 wt.% olefinic elastomer and a 10-30 wt.% pressure-sensitive adhesive agent. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a glass bottle equipped with a thermal label. More specifically, the present invention relates to a labeled glass bottle comprising a glass bottle having a resin coating layer excellent in recyclability, and a heat-sensitive label having excellent adhesion and easy peelability to the glass bottle.

  In addition to glass bottles for use in alcoholic beverages and soft drinks, colored glass bottles are used for the purpose of imparting decorativeness and shielding light. As these colored bottles, the glass bottles themselves have been colored, but recently, glass bottles colored by coating a transparent glass bottle with a thin film of resin have been used. Glass bottles colored with these resin coatings (plastic coatings) have an advantage of excellent recyclability because the glass itself is transparent when the resin coating is removed. Moreover, these glass bottles have the advantage of the strength improvement by the reinforcement effect by a resin layer.

  Usually, a plastic label is often attached to the glass bottle for providing display, decoration, and functionality. For example, a thermal label is used. These labels are required to have excellent adhesion to glass bottles when used, and from the viewpoint of recycling, they need to be easily peelable from glass bottles after use without causing adhesive residue, etc. Has been.

  For a conventional glass bottle, a heat-sensitive label having a heat-sensitive adhesive layer composed of an olefin polymer and a tackifier is known as a heat-sensitive label having both adhesion and easy peeling (for example, Patent Document 1). 2). However, in the case of the glass bottle coated with the resin, a wax or a lubricant is added to the resin coating layer in order to improve the slipperiness peculiar to the resin. The heat-sensitive label cannot obtain a sufficient adhesion and cannot be used.

  On the other hand, as means for solving the problem of adhesion to a glass bottle, a heat-sensitive label having an adhesive layer containing a silane coupling agent and a glass bottle with a label (for example, see Patent Documents 3 and 4) are known. However, since these heat-sensitive labels are firmly bonded to the glass bottle side by chemical bonding or the like, there is a problem that peeling after use is difficult and adhesive residue is generated, which is not suitable for recycling. In addition, there is a problem in terms of productivity, for example, it is necessary to perform special surface processing in the glass bottle manufacturing process.

  As mentioned above, the present condition is that the thermosensitive label which was compatible with adhesiveness and easy peelability with respect to the glass bottle which gave the thin film coating was not obtained.

JP 2003-291242 A JP 2005-62321 A JP-A-8-44295 JP 2001-31095 A

  An object of the present invention is to provide a glass bottle with a label that exhibits excellent adhesion to a resin-coated glass bottle, and that is equipped with a heat-sensitive label that can be easily peeled off after use without any adhesive residue. There is.

  As a result of intensive studies to achieve the above object, the inventors of the present invention attached a heat-sensitive label having a heat-sensitive adhesive layer having a specific composition to a glass bottle having a specific resin coating layer. And found that a glass bottle with a heat-sensitive label excellent in easy peelability can be obtained, and the present invention has been completed.

  That is, in the present invention, an ethylene-vinyl acetate copolymer 20 to 70% by weight, an olefin-based elastomer 20 to 20% on the outer surface of a glass bottle having a resin coating layer having a thickness of 5 to 20 μm mainly composed of a resin having a polar group. Provided is a glass bottle with a heat-sensitive label, which is provided with a heat-sensitive label having a heat-sensitive adhesive layer comprising a heat-sensitive adhesive containing 50% by weight and a tackifier of 10 to 30% by weight.

  Furthermore, this invention provides the glass bottle with the said heat-sensitive label whose resin which has a polar group is at least 1 sort (s) of resin chosen from the acrylic resin, the urethane resin, and the epoxy resin.

  Furthermore, this invention provides the glass bottle with the said heat-sensitive label whose ethylene component content of an ethylene-vinyl acetate copolymer is 65 to 90 weight% and vinyl acetate component content is 10 to 35 weight%.

  Furthermore, the present invention provides the above glass bottle with a heat-sensitive label, wherein the olefin elastomer is an α-olefin copolymer elastomer.

  Since the glass bottle with a heat-sensitive label of the present invention has excellent label adhesion, it has good decorativeness and handleability and is unlikely to cause quality problems. Further, after use, the label can be easily peeled off and no adhesive residue is left on the side of the glass bottle. The used glass bottle can be easily recycled and is excellent in terms of environment. For this reason, the glass bottle with a heat-sensitive label of the present invention is useful as various containers such as beverages, foods and seasonings.

  Below, the glass bottle with a thermosensitive label of this invention is demonstrated in detail.

  The glass bottle with a heat-sensitive label of the present invention is formed by mounting a heat-sensitive label on a glass bottle. The heat-sensitive label may be attached by being wrapped around the body of the glass bottle or may be attached by being attached to a part of the body or shoulder of the glass bottle. However, it is preferable that the thermosensitive label is attached to a portion of the glass bottle on which the resin coating is applied (that is, on the resin coating layer). The effect of the present invention may not be exhibited when it is attached to a portion where the resin coating is not applied (such as a portion where the glass itself is exposed).

  First, the thermal label of the present invention will be described.

  The heat-sensitive label used for the glass bottle with the heat-sensitive label of the present invention has a label substrate, and at least a layer made of a heat-sensitive adhesive on the surface that becomes the glass bottle side when mounted on the glass bottle (hereinafter referred to as a heat-sensitive adhesive layer). Is provided. Preferably, it is provided only on the surface on the glass bottle side. The heat-sensitive adhesive layer may be provided on the entire surface of the label base material, or may be provided only on a part (for example, a belt shape). In addition to the heat-sensitive adhesive layer of the present invention, the heat-sensitive label of the present invention has a printed layer, a coating layer, a resin layer, an anchor coat layer, a primer coat layer, a top coat layer, and an adhesive other than the adhesive layer of the present invention. An agent layer or the like can be provided, and a layer of non-woven fabric, paper, plastic, or the like may be provided as necessary. Examples of the layer structure of the heat-sensitive label include a label base material / printing layer / heat-sensitive adhesive layer, topcoat layer / printing layer / label base material / heat-sensitive adhesive layer, and the like.

  The heat-sensitive adhesive layer of the present invention comprises an ethylene-vinyl acetate copolymer (copolymer having ethylene and vinyl acetate as essential monomer components), an olefin elastomer, and a heat-sensitive adhesive having a tackifier as essential components. . The ethylene-vinyl acetate copolymer and tackifier play a role of tackiness and adhesiveness, and the olefin elastomer mainly plays a role of increasing the cohesive strength of the adhesive layer and developing easy peeling, and preventing adhesive residue. To bear. In addition to the above essential components, if necessary, various additives may be contained in addition to the above. Examples of the additives include emulsifiers, waxes, modifiers, pigments, and dyes. , Lubricants, antioxidants, UV absorbers, antistatic agents, fluorescent whitening agents, anti-blocking agents, flame retardants, foaming agents, reinforcing agents, fillers, leveling regulators, thickeners, antifoaming agents, surface activity Agents, fungicides, neutralizers, fragrances, antifreeze agents, crosslinking agents, deodorants, stabilizers and the like.

  The ethylene-vinyl acetate copolymer used in the heat-sensitive adhesive of the present invention is a copolymer having ethylene and vinyl acetate as essential monomer components, and, if necessary, further copolymerizable monomer components are copolymerized. May be. Examples of copolymerizable monomer components include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, and (meth) acrylic. (Meth) acrylic acid alkyl esters such as 2-ethylhexyl acid, n-hexyl (meth) acrylate, lauryl (meth) acrylate, (meth) acrylic acid, maleic acid, itaconic acid, 2-hydroxy (meth) acrylic acid Examples include ethyl, hydroxypropyl (meth) acrylate, (meth) acrylamide, N-methylol acrylamide, diacetone acrylamide, styrene, vinyl toluene, acrylonitrile and the like. These copolymerizable monomer components may be used alone or in combination of two or more. The above “(meth) acrylic acid alkyl ester” means “acrylic acid alkyl ester and / or methacrylic acid alkyl ester”. Others are the same.

  The ethylene-vinyl acetate copolymer of the present invention is also available on the market. Examples of commercially available products include "Evaflex EV250, EV450, EV150" manufactured by Mitsui DuPont Polychemical Co., Ltd., Sumitomo Chemical Co., Ltd. “Evalate H4011, K4010” and the like are available.

  The ethylene component content of the ethylene-vinyl acetate copolymer of the present invention is preferably 65 to 90% by weight, more preferably 70 to 80% by weight, based on the total amount of monomer components. The vinyl acetate component content is preferably 10 to 35% by weight, more preferably 20 to 30% by weight. When two or more ethylene-vinyl acetate copolymers are mixed and used, the total amount of all ethylene components and the total amount of all copolymerization monomer components in the ethylene-vinyl acetate copolymer mixture are within the above range. Is preferably satisfied. When the ethylene component content is outside the above range, tackiness may be reduced or blocking may occur.

  When the ethylene-vinyl acetate copolymer of the present invention contains other copolymerization monomer components, the copolymerization monomer component content is preferably 10% by weight or less, more preferably based on the total amount of monomer components. Is 5% by weight or less. Most preferably, only ethylene and vinyl acetate are used as monomer components without using other copolymerization monomer components.

  The weight average molecular weight of the ethylene-vinyl acetate copolymer of the present invention is preferably 50,000 to 500,000, more preferably 100,000 to 300,000 from the viewpoint of resin strength.

  The melt flow rate (MFR) (temperature 230 ° C., load 2.16 kg) of the ethylene-vinyl acetate copolymer of the present invention is preferably 5 to 40 g / 10 minutes from the viewpoints of flexibility, resin strength, and adhesive residue. More preferably, it is 5 to 25 g / 10 minutes.

  In the heat-sensitive adhesive layer of the present invention, the content of the ethylene-vinyl acetate copolymer is 20 to 70% by weight, preferably 25 to 65% by weight, more preferably 30 to 60% by weight. When the content of the ethylene copolymer is less than 20% by weight, the adhesiveness is lowered. Moreover, when content exceeds 70 weight%, easy peelability falls or blocking arises.

  The olefin-based elastomer used in the heat-sensitive adhesive of the present invention is a copolymer having an α-olefin as a monomer component, and is preferably a copolymer of ethylene and an α-olefin other than ethylene. The olefin-based elastomer is a resin that does not contain a polar group and provides adhesion to an adherend. Although it does not specifically limit as alpha olefins other than ethylene, Propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1- An α-olefin having about 3 to 20 carbon atoms such as decene may be mentioned. Furthermore, a ternary copolymer obtained by copolymerizing a diene component such as 5-ethylidene-2-norbornene, dicyclopentadiene, 1,4-hexadiene as the third component may be used.

  The olefin-based elastomer of the present invention is also available in the market. Examples of commercially available products include “Tuffmer P-0280” manufactured by Mitsui Chemicals, Inc., “Sumitomo TPE 817, 821” manufactured by Sumitomo Chemical Co., Ltd., and the like. Can be mentioned.

  The weight average molecular weight of the olefin elastomer of the present invention is preferably 50,000 to 500,000, more preferably 100,000 to 300,000 from the viewpoint of adhesion.

  The MFR of the olefin-based elastomer of the present invention is preferably 1 to 20 g / 10 minutes, more preferably 3 to 15 g / 10 minutes from the viewpoint of film strength.

  In the heat-sensitive adhesive layer of the present invention, the content of the olefin elastomer is 20 to 50% by weight, preferably 25 to 45% by weight, and more preferably 25 to 40% by weight. When the content of the tackifier is less than 20% by weight, the cohesive force of the heat-sensitive adhesive layer is reduced, and adhesive residue tends to occur. Moreover, when content exceeds 50 weight%, adhesive force falls.

  The tackifier used in the heat-sensitive adhesive of the present invention has an effect of improving adhesion, for example, terpene resin, rosin resin, petroleum resin, coumarone-indene resin, styrene resin, phenol. Resins can be used. A tackifier can be used individually or in combination of 2 or more types. As the tackifier, a terpene resin can be preferably used.

  Examples of terpene resins include terpene resins, aromatic modified terpene resins, hydrogenated terpene resins, terpene-phenol resins, and the like. Examples of the rosin resin include rosin, polymerized rosin, hydrogenated rosin and derivatives thereof, and resin acid dimer. The petroleum resin may be any of aliphatic, aromatic and alicyclic petroleum resins.

  The tackifier of the present invention is also available on the market, and examples thereof include “Clearon P115, P105, P95” manufactured by Yashara Chemical Co., Ltd. and “R-100AS” manufactured by Maruzen Petrochemical Co., Ltd.

  In the heat-sensitive adhesive layer of the present invention, the content of the tackifier is 10 to 30% by weight, preferably 15 to 25% by weight. When the content of the tackifier is less than 10% by weight, the adhesiveness is lowered. Moreover, when content exceeds 30 weight%, it is easy to produce blocking and productivity, workability | operativity, etc. fall.

  In addition to the above essential components, the heat-sensitive adhesive of the present invention preferably contains a lubricant as an additive from the viewpoint of productivity and blocking resistance. As the lubricant, a known solid or liquid lubricant can be used. For example, polyolefin wax such as polyethylene wax and fluorine-modified polyethylene wax, fatty acid amide, fatty acid ester, paraffin wax, polytetrafluoroethylene (PTFE). ) Various waxes such as wax and carnauba wax are exemplified. The content of the lubricant is preferably 0.05 to 3% by weight in the heat-sensitive adhesive layer. For example, it is preferably about 500 to 10,000 ppm for amide type lubricants and about 0.1 to 3% by weight for polyethylene waxes.

  The heat-sensitive adhesive of the present invention preferably contains substantially no compound having a condensation reactive group such as a condensable silyl group. Examples of the condensable silyl group include a silanol group and a hydrolyzable silyl group (for example, a methoxysilyl group, an ethoxysilyl group, etc.). Examples of the compound having this include, for example, JP-A-8-44295 and JP-A-2001-31095. The compound which added silane coupling agents, such as the silane graft modified body of the olefin polymer which has an epoxy group as described in above. The “substantially free” means, for example, that the content with respect to the heat-sensitive adhesive is 1% by weight or less (preferably 0.5% by weight or less). When the compound having a condensation reactive group exceeds 1% by weight, the heat-sensitive adhesive layer of the present invention and the resin coating layer of the glass bottle are firmly bonded by chemical adhesion by the condensation reaction. May decrease and adhesive residue may be generated, resulting in poor recyclability.

  The MFR of the heat-sensitive adhesive of the present invention is, for example, preferably 5 to 40 g / 10 minutes, more preferably 10 to 30 g / 10 minutes. When the MFR of the heat-sensitive adhesive is less than 5 g / 10 minutes, the activation temperature becomes high and the adaptability of the heat-sensitive labeler may decrease. On the other hand, when it exceeds 40 g / 10 minutes, the ratio of the low molecular weight component and the additive component increases, and the adhesive force change with time may increase.

  The stress at break (based on JIS-K-6760) of the heat-sensitive adhesive of the present invention is preferably about 0.5 to 5 MPa. If the stress at break is less than 0.5 MPa, cohesive failure is likely to occur. On the other hand, if it exceeds 5 MPa, the activation temperature is high and sticking to the container may be difficult.

  The elongation (based on JIS-K-6760) of the heat-sensitive adhesive of the present invention is preferably about 200 to 1500%. If the elongation is less than 200%, cohesive failure is likely to occur. On the other hand, if it exceeds 1500%, it may be difficult to peel the label manually.

  The Vicat softening point of the heat-sensitive adhesive of the present invention is preferably about 20 to 60 ° C. If the Vicat softening point is less than 20 ° C, the heat-sensitive adhesive surface of the easily peelable thermosensitive label becomes difficult to be blocked at room temperature, and if it exceeds 60 ° C, the activation temperature is high and sticking is performed. May decrease.

  The label substrate used for the heat-sensitive label of the present invention can be appropriately selected in consideration of heat resistance, handleability, printability, etc., for example, paper or synthetic paper, plastic film, plastic sheet, metal foil such as aluminum foil, Nonwoven fabrics or laminates thereof can be suitably used. Examples of the paper include water-resistant paper such as art paper and coated paper, and Japanese paper. Examples of the synthetic paper include void-containing synthetic paper (such as “Chrisper” manufactured by Toyobo Co., Ltd.), internal paper synthetic paper (such as “Yupo” manufactured by YUPO Corporation), and surface-coated synthetic paper ( Nisshinbo Co., Ltd. “Peach Coat”, etc.), spunbond synthetic paper (DuPont “TYVEK”, etc.) and the like.

  The plastic film can be appropriately selected according to required physical properties, applications, costs, and the like, and is not particularly limited. For example, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), poly ( Polyester resins such as ethylene-2,6-naphthalenedicarboxylate (PEN); Polyolefin resins such as polyethylene and polypropylene; Polystyrene resins such as styrene-butadiene copolymers; Polyvinyl chloride, Polyamide, Aramid, Polyimide, Polyphenylene sulfide And a film made of a resin such as acrylic. These may be used singly or in combination of two or more.

  The plastic film may be a single-layer film or a laminated film in which a plurality of film layers are laminated according to required physical properties, applications, and the like. In the case of a laminated film, film layers made of different resins may be laminated. For example, it may be a three-layer laminated film composed of a central layer and a surface layer portion (inner layer, outer layer), a film in which the central layer is composed of a polyolefin resin or a polystyrene resin, and a surface layer is composed of a polyester resin. Moreover, according to a required physical property, a use, etc., any of an unstretched film, a uniaxially oriented film, and a biaxially oriented film may be used, and either a heat shrinkable film or a non-heat shrinkable film can be used. Moreover, foamed plastic films, such as a foamed polystyrene film, a foamed polyester film, and a foamed polyolefin film, may be sufficient.

  Among the above, a non-heat-shrinkable film such as an unstretched film or a biaxially stretched film is used for the label substrate of the present invention, and in particular, a biaxially stretched polypropylene film (OPP) and a biaxially stretched PET A film or the like is used. Commercially available products can be used for these plastic films. For example, OPP film “FOS” manufactured by Futamura Chemical Co., Ltd. and biaxially stretched PET film “S” manufactured by Unitika Co., Ltd. are available on the market. is there.

  The thermal contraction rate of the label base material is not particularly limited, but it is preferably less than 5% in both the MD direction and the TD direction, more preferably less than 1% under the condition of immersion in hot water at 90 ° C. for 5 seconds. If the heat shrinkage rate is 5% or more, the label may shrink due to heat at the time of sticking, and wrinkles or misalignment may occur. Furthermore, 5% or less is preferable on the conditions immersed in a 100 degreeC glycerol bath for 5 second, More preferably, it is 1% or less.

  Although the thickness of a label base material can be suitably selected in the range which does not impair mechanical strength, the handleability of a label, etc., it is about 5-200 micrometers, for example, Preferably it is about 10-60 micrometers.

  The layer thickness of the heat-sensitive adhesive layer in the heat-sensitive label of the present invention is preferably 5 to 50 μm, more preferably 15 to 40 μm. If the thickness of the heat-sensitive adhesive layer is less than 5 μm, it may be difficult to laminate uniformly and the adhesion may be reduced. If it exceeds 50 μm, the adhesive residue due to destruction of the heat-sensitive adhesive layer at the time of peeling. May occur.

  You may provide a printing layer in the thermosensitive label of this invention. The printing layer is usually a layer that displays characters, such as product names, handling precautions, and various information such as campaigns, as well as graphics, patterns, images, and the like as decorations. The printing layer can be formed by a conventional printing method such as letterpress printing, silk screen printing, gravure printing or flexographic printing. The printing ink used for forming the printing layer is composed of, for example, a pigment, a binder resin, and a solvent. Examples of the binder resin include acrylic, urethane, polyamide, vinyl chloride-vinyl acetate copolymer, cellulose, and nitro. Common resins such as cellulose can be used. The thickness of the printing layer is not particularly limited and is, for example, about 0.1 to 10 μm. Moreover, you may form a printing layer with an ultraviolet curable ink.

  The heat-sensitive label of the present invention is produced by forming an adhesive layer with the heat-sensitive adhesive on at least one side of a label substrate such as the plastic film. The heat-sensitive adhesive is prepared by mixing a predetermined amount of each of the above components by a melt kneading method. A melt extrusion coating method is preferably used as the method for forming the adhesive layer with the heat-sensitive adhesive. The heat-sensitive adhesive is put into a heated monoaxial or biaxial extruder and melt-extruded from a T-shaped die or the like onto a label substrate (or printed layer) to form a heat-sensitive adhesive layer. In this case, the extrusion resin temperature is preferably 150 to 300 ° C., and the residence time is preferably about 5 to 60 minutes. In addition, although the said heat sensitive adhesive layer may be provided on the printing layer, it needs to be provided as the outermost layer of a heat sensitive label for the function expression of an adhesive layer.

  The shape and size of the thermosensitive label of the present invention are not particularly limited, and can be appropriately selected depending on the shape and size of the glass bottle. In addition, in the case of a long length, it can be slit into a predetermined width, wound into a roll shape, and stored as a roll-shaped object.

  Below, the glass bottle of this invention is demonstrated.

  In the glass bottle of the present invention, a resin coating layer mainly composed of a resin having a polar group is provided on the outside of a transparent glass bottle (or a colored glass bottle). The coating layer exhibits effects such as imparting decorativeness to the transparent glass bottle by a coloring effect, improving the strength by resin coating, and protecting the contents by shading. The “glass bottle” referred to in the present invention is not particularly limited in shape and size, and includes “glass containers” and the like.

  The resin coating layer of the present invention is mainly composed of a resin having a polar group from the viewpoint of adhesion to glass. Examples of the polar group include an ester group, an epoxy group, and a hydroxyl group, and examples of the resin include acrylic resins, epoxy resins, oxetane resins, urethane resins, vinyl ether resins, and unsaturated polyester resins. And silicone resins.

  The resin for forming the resin coating layer of the present invention is a resin by active energy ray curing or thermosetting (hereinafter referred to as active energy ray curable resin and thermosetting type, respectively) from the viewpoint of imparting toughness of the coating layer and imparting abrasion resistance. Resin)). As the active energy ray curable resin, an acrylic resin, an unsaturated polyester resin, and the like are preferable, and an acrylic resin is particularly preferable. The thermosetting resin is preferably an epoxy resin, a urethane resin, or a silicone resin, and particularly preferably an epoxy resin or a urethane resin.

  The active energy ray-curable acrylic resin is obtained by curing a composition (hereinafter referred to as a coating agent) containing an active energy ray polymerizable compound (hereinafter referred to as a photopolymerizable compound) as an essential component. In addition, the coating agent may contain a reactive diluent (monomer), an active energy ray polymerization initiator (hereinafter referred to as a photopolymerization initiator), and a solvent as necessary.

  The photopolymerizable compound is a compound having 2 or more (meth) acryloyl groups or fluoroacryloyl groups in the molecule, and preferably 2 to 6 compounds. Such a compound is not particularly limited. For example, a polyvalent (meth) acrylate that is a reaction product of a polyhydric alcohol and (meth) acrylic acid, an epoxy compound having two or more epoxy groups in the molecule ( Epoxy (meth) acrylate, which is a reaction product of (meth) acrylic acid, polyester (meth) acrylate, which is a reaction product of polyester polyol and (meth) acrylic acid, and a reaction product of polyisocyanate and hydroxyl group-containing (meth) acrylate. Examples include polyurethane (meth) acrylate, polyvalent fluoroacrylate, and epoxy-modified fluoroacrylate. Among these, polyvalent (meth) acrylate and epoxy (meth) acrylate are particularly preferable.

  Examples of the polyvalent (meth) acrylate include diethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, bisphenol A di (meth) acrylate, and trimethylol. Examples thereof include propane tri (meth) acrylate and dipentaerythritol hexa (meth) acrylate.

  Examples of the epoxy-modified (meth) acrylate include bisphenol A epoxy-modified (meth) acrylate, glycerol diglycidyl ether-modified (meth) acrylate, neopentyl glycol diglycidyl ether-modified (meth) acrylate, and ethylene glycol diglycidyl ether-modified ( And (meth) acrylate.

  The reactive diluent has the role of controlling the viscosity of the coating agent, the reactivity, the hardness of the resin coating layer after curing, etc. to the desired physical properties, and is active energy ray polymerizable such as monofunctional or polyfunctional acrylate. A monomer component is preferably used. Such as, for example, 2-ethylhexyl acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxyethylacryloyl phosphate, tetrahydrofurfuryl (meth) acrylate, dicyclopentenyl Examples include (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, and isobornyl (meth) acrylate.

  The photopolymerization initiator used in the coating agent may be a known photoradical polymerization initiator or photoion (cation, anion) polymerization initiator, although it varies depending on the type of resin used. Examples of photo radical polymerization initiators used for acrylic resins include, for example, benzoin, benzoin alkyl ethers, benzyl ketals, acetophenone, α-hydroxycyclohexyl phenyl ketone, acetophenone derivatives, benzyl, benzophenone, benzophenone derivatives, α-acylose. Examples include oxime esters, thioxanthone derivatives, anthraquinone derivatives, and aromatic peroxide esters. These may be used alone or in admixture of two or more. Examples of the ionic polymerization initiator include aryl diazonium compounds, diaryl iodonium compounds, triaryl sulfonium compounds, triaryl selenonium compounds, and the like. Moreover, you may use together with aromatic amines, such as ethyl p-dimethylaminobenzoate and isoamyl p-dimethylaminobenzoate.

  Visible light, ultraviolet light, an electron beam, etc. can be used for the active energy ray used for hardening of the said coating agent. A preferable absorption wavelength is 300 to 460 nm.

  The thermosetting epoxy resin can be obtained by using a known epoxy compound having at least one epoxy group in its molecule (such as an aliphatic epoxy compound, an alicyclic epoxy compound, or an aromatic epoxy compound). . Examples of the epoxy compound include propylene glycol glycidyl ether, 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, bis- (3,4-epoxycyclohexyl) adipate, bisphenol A glycidyl ether, bisphenol A Glycidyl ether condensates, phenol or resorcin-derived epoxy compounds, epichlorohydrin modified products of novolak resins and cresol resins, aromatic carboxylic acid-derived epoxy compounds, vinyl polymer-derived epoxy compounds, and the like. Epoxy resins can be obtained from these compounds and amine-based or organic acid anhydride-based curing agents.

  Examples of the thermosetting urethane resin include polyols selected from polyester polyols obtained by copolymerization of polyols and polycarboxylic acids, glyceride esters of castor oil or other hydroxylated fatty acids, polyalkylene glycols, and organic polyisocyanates. Can be obtained from a composition comprising

  The resin coating layer of the present invention preferably contains a lubricant. As the lubricant, a known solid or liquid lubricant can be used, for example, silicone oil, polyethylene wax, polyolefin wax such as fluorine-modified polyethylene wax, fatty acid amide, fatty acid ester, paraffin wax, polytetrafluoroethylene. Various waxes such as (PTFE) wax and carnauba wax are exemplified. When the resin coating layer of the present invention is used without a lubricant, the slipperiness is poor and the handling property in the process may be lowered. The addition amount of the lubricant is 0.5 to 2% by weight with respect to the entire resin coating layer. The heat-sensitive label of the present invention is preferable because it exhibits excellent adhesion even to a resin coating layer containing such a lubricant.

  When the glass bottle is colored in order to impart decorativeness, colorants such as pigments and dyes can be added to the resin coating layer of the present invention. In particular, it is preferable to contain a pigment. Organic, inorganic, and colored pigments can be used as pigments. White pigments such as titanium oxide (titanium dioxide), indigo pigments such as copper phthalocyanine blue, carbon black, aluminum flakes, and mica (mica) are selected according to the application. Can be used. In addition, extender pigments such as alumina, calcium carbonate, barium sulfate, silica, and acrylic beads can also be used as pigments for the purpose of adjusting gloss and frosting. When adding a pigment, the addition amount of the pigment is preferably 5 to 30% by weight based on the resin.

  An ultraviolet absorber may be added to the resin coating layer of the present invention for the purpose of shielding ultraviolet rays and preventing deterioration of contents. Examples of the ultraviolet absorber include 2-hydroxybenzophenone, 5-chloro-2-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, 4- Benzophenone ultraviolet absorbers such as dodecyloxy-2-hydroxybenzophenone and 2,2 ′, 4,4′-tetrahydroxybenzophenone; 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy- 3-t-butyl-5-methylphenyl) benzotriazole, 2- (2-hydroxy-3,5-di-t-butylphenyl) benzotriazole, 2- (2-hydroxy-5-t-octylphenyl) benzo Triazole, 2- (2-hydroxy-3 Benzotriazole ultraviolet absorbers such as 5-di-t-amylphenyl) benzotriazole; benzoate ultraviolet rays such as 2,4-di-t-butylphenyl-3,5-di-t-butyl-4-hydroxybenzoate Absorbers; salicylic acid ultraviolet absorbers; cyanoacrylate ultraviolet absorbers and the like.

  A silane coupling agent may be added to the coating agent of the present invention for the purpose of improving the adhesion between the glass bottle and the resin coating layer. As the silane coupling agent, known ones can be used. For example, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropylmethyldimethoxysilane, γ-acryloxypropyltriethoxysilane, γ-methacryloxy Examples include propyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane.

  In addition to the above additives, the coating agent of the present invention includes a solvent, a leveling agent, a dispersant, a fragrance, a deodorant, a stabilizer, an antifoaming agent, a surfactant, an antioxidant, and a modification, as necessary. An agent or the like may be added.

  The coating agent of the present invention is prepared by simultaneously mixing the above-described components, for example, a photopolymerizable compound comprising acrylate, a reactive diluent, a photopolymerization initiator, a solvent, and various additives. For mixing, a mixer such as a butterfly mixer, a planetary mixer, a pony mixer, a dissolver, and a tank mixer, a mill such as a roll mill, a sand mill, a ball mill, a bead mill, and a line mill, and a kneader are used. The mixing temperature during mixing is preferably 15 to 30 ° C., and the mixing time (residence time) is preferably 10 to 120 minutes. The obtained coating agent may be filtered and used for coating, if necessary.

  The glass bottle of the present invention is produced by coating the above coating agent on the outside of a normal transparent glass bottle (drying if necessary) and then curing it with active energy rays or heat to form a resin coating layer. The coating method is not particularly limited, but a dip coating method (immersion method) is preferably used from the viewpoints of productivity, workability, and the like. Curing with an active energy ray uses, for example, an ultraviolet (UV) lamp, a mercury lamp, a xenon lamp, a carbon arc lamp, a tungsten lamp, or the like. In the case of thermosetting, a hot air tunnel, an infrared oven, or the like can be used.

  The resin coating layer of the present invention has a thickness of 5 to 20 μm, preferably 10 to 15 μm. When the thickness of the resin coating layer is less than 5 μm, the strength improvement and the light shielding effect are reduced. Moreover, when thickness exceeds 20 micrometers, since the resin is used in large quantities, the cost with respect to an effect becomes high, and also productivity falls.

  Furthermore, the glass bottle with a heat-sensitive label of the present invention will be described.

  The glass bottle with a heat-sensitive label of the present invention can be produced by mounting the heat-sensitive label on the glass bottle. The heat-sensitive label can be attached to the glass bottle by a known or conventional method. For label mounting, for example, the surface of the thermal label on the thermal adhesive layer side is overlaid on the container surface, a hot plate is pressed from the label substrate side, or the thermal label is sucked from the label substrate side to the heating drum. The heat-sensitive adhesive layer is activated by applying heat to the heat-sensitive adhesive layer with a heat source such as heat from infrared rays or infrared rays (to make the adhesive state expressed by softening or melting), and then applied. Usually, a labeler (label automatic sticking machine: described in, for example, JP-A-8-58755, JP-A-11-321831, JP-A-2000-25725) is used. Is used). In the glass bottle with a heat-sensitive label of the present invention, as described in JP-A-2001-31095, sufficient adhesion can be exhibited even if the resin coating layer of the glass bottle is not subjected to surface treatment such as flame treatment. This is preferable because it is possible. The heating temperature of the thermosensitive label is appropriately selected according to the activation temperature of the thermosensitive adhesive layer, and is preferably, for example, 70 to 150 ° C, more preferably 80 to 120 ° C. The activation temperature of the adhesive layer here means an adhesive strength (conforming to JIS Z 0237) of 0.1 N / 15 mm or more with a non-shrinkable PET film (Toyobo Co., Ltd. “A1101”) as an adherend. This is the temperature that occurs.

  The glass bottle having the thermosensitive label of the present invention and the resin coating layer is physically bonded by intermolecular force or the like. Both have moderately high affinity due to the polar group of the heat-sensitive label and the polar group of the resin coating layer, and exhibit good adhesion, so that troubles such as label peeling during processing and distribution do not occur. Since the heat-sensitive label of the present invention uses an ethylene-vinyl acetate copolymer as a main agent, it is suitable for sticking at low temperature (for example, 70 to 100 ° C.), suitable strength selectivity, compatibility with various additives, etc. High effect can be obtained. In the case of other ethylene-vinyl monomer copolymers, it is difficult to achieve both low temperature sticking suitability and appropriate strength. On the other hand, as described above, since the heat-sensitive adhesive layer of the label has substantially no condensation-reactive functional group, very strong chemical adhesion as in JP-A-2001-31095 does not occur. For this reason, when peeling a label after use, it becomes possible to peel easily without adhesive residue, and it is excellent also in recyclability. In addition, the thermosensitive resin for thermosensitive labels of the present invention has a high molecular weight (100,000 to 300,000) compared to the molecular weight (20000 to 50,000) of the type of resin that is applied using a hot melt applicator, etc. Has the advantage of high stability over time and little variation in adhesive strength due to the season.

  In the present invention, the adhesive strength of the thermosensitive label to the glass bottle having the resin coating layer is preferably 0.1 to 5.0 (N / 15 mm), more preferably 0.3 to 3.0 (N / 15 mm). . If the adhesive strength is less than 0.1 (N / 15 mm), it may be easily peeled off during processing and distribution, and may not endure use as a label. Moreover, when adhesive force exceeds 5.0 (N / 15mm), when peeling after use, peeling may become difficult and an adhesive residue may be produced.

  The glass bottle with a heat-sensitive label of the present invention includes, for example, sake bottles for sake, beer and wine, soft drink bottles for juice, food and seasoning bottles for milk bottles, jam and mayonnaise, chemicals, nutrition drinks, etc. It is preferably used for glass containers such as tablets and drinks / medicine bottles and pudding containers.

[Methods for measuring physical properties and methods for evaluating effects]

(1) Adhesiveness (initial adhesive strength, post-adhesive strength), easy peelability The label portion of the glass bottle with a heat-sensitive label obtained in Examples and Comparative Examples was cut into a label circumferential direction with a width of 15 mm, and peel strength Measurements were made.
In accordance with JIS-Z-0237, a 90 ° peel test was performed under the following conditions, and the adhesive strength (N / 15 mm) with an average value of the peel load with a peel length (crosshead travel distance) of (50 mm to 150 mm) It was. The measurement direction is the circumferential direction of the label.
The adhesive strength measured after leaving the sample for 20 minutes under conditions of 23 ° C. and 50% RH was taken as the initial adhesive strength. In addition, after the sample was prepared, the adhesive strength measured after standing for 30 days under the conditions of 23 ° C. and 50% RH was defined as the adhesive strength after aging.
If the initial adhesive strength and the post-aging adhesive strength are in the range of 0.1 to 5.0 (N / 15 mm), any of the adhesiveness and easy peelability (◯), the initial adhesive strength, or the post-aging adhesive strength is 0. When it was less than 0.1 (N / 15 mm), it was judged as poor adhesion (x), and when it exceeded 5.0 (N / 15 mm), it was judged as easy peelability (x).
Measuring device: Shimadzu Corporation autograph (AGS-50G: load cell type 500N)
Temperature and humidity: Temperature 23 ± 2 ° C, humidity 50 ± 5% RH (JIS K 7000 standard temperature state 2nd grade)
Sample width: 15mm
Number of tests: 3 times Crosshead moving speed: 300 mm / min

(2) Adhesive residue When the glass bottle after the peel test of (1) above is visually observed, no adhesive residue is observed on the glass bottle side (good), and poor adhesive residue is observed on the glass bottle side. (X) was judged.

(3) Label substrate thickness, heat-sensitive adhesive layer thickness The thickness of a label substrate such as a plastic film was measured using a stylus type thickness gauge. In addition, the thickness of the heat-sensitive adhesive layer is determined by using a three-dimensional microscope (VK8510 manufactured by Keyence Corporation) as the level difference between the portion where the adhesive layer is provided (application surface) and the portion where the adhesive layer is not provided (non-application surface). And measured.

  EXAMPLES Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. In addition, the addition amount of each component is represented by the weight% in a heat sensitive adhesive.

Example 1
(Thermal label)
Ethylene-vinyl acetate copolymer (“Evaflex EV250” manufactured by Mitsui DuPont Polychemicals, ethylene content 72%, vinyl acetate content 28%, MFR: 30 g / 10 min) 50% by weight, ethylene- α-olefin copolymer (“Tafmer P-0280” manufactured by Mitsui Chemicals, Inc., MFR: 2.9 g / 10 min) 30% by weight, hydrogenated terpene resin (“Clearon P115” manufactured by Yasuhara Chemical Co., Ltd.) as a tackifier ”, 20% by weight of ring and ball method softening point: 115 ° C.) was melt-kneaded to prepare a heat-sensitive adhesive. The MFR of the heat-sensitive adhesive was 22 g / 10 minutes.
Next, using the single screw extruder which heated the said heat sensitive adhesive at 180-235 degreeC, on PET film ("E5100" by Toyobo Co., Ltd., base material thickness: 50 micrometers) which is a label base material. Then, a T-die melt extrusion was performed to form a heat-sensitive adhesive layer (thickness 25 μm), and a heat-sensitive label was produced.

(Glass bottle with thermal label)
A glass bottle coated with an active energy ray-curable acrylic resin (1.5% by weight of polyethylene wax added) at a thickness of 8 μm was used on a glass bottle (manufactured by Nippon Yamamura Glass Co., Ltd., standard “720N”).
Place the heat-sensitive label obtained above on a hot plate heated to 100 ° C. with the glue surface facing upward, and apply a pressure of 10 to 15 kg on the resin-coated glass bottle preheated to 60 to 70 ° C. The glass bottle with a heat-sensitive label was produced by pressure-bonding to the glass bottle.

  As shown in Table 1, the obtained glass bottle with a heat-sensitive label had little adhesive residue and had excellent adhesiveness and easy peelability.

Example 2
As shown in Table 1, a glass bottle with a thermosensitive label was obtained in the same manner as in Example 1 except that the coating resin for the glass bottle was changed to a thermosetting epoxy resin (thickness: 6 μm).
As shown in Table 1, the obtained glass bottle with a heat-sensitive label had little adhesive residue and had excellent adhesiveness and easy peelability.

Examples 3-6
As shown in Table 1, a heat-sensitive label and a glass bottle with a heat-sensitive label were prepared in exactly the same manner as in Example 1 except that the ethylene-vinyl acetate copolymer, the olefin elastomer, the type of tackifier, and the amount added were changed. Produced.
As shown in Table 1, the obtained glass bottle with a heat-sensitive label had little adhesive residue and had excellent adhesiveness and easy peelability.

Comparative Examples 1-4
As shown in Table 1, a heat-sensitive label and a glass bottle with a heat-sensitive label were prepared in exactly the same manner as in Example 1 except that the ethylene-vinyl acetate copolymer, the olefin elastomer, the type of tackifier, and the amount added were changed. Produced.
As shown in Table 1, the obtained glass bottle with a heat-sensitive label was inferior in adhesiveness, easy peelability and adhesive residue.

Claims (4)

  On the outer surface of a glass bottle having a resin coating layer having a thickness of 5 to 20 μm mainly composed of a resin having a polar group, 20 to 70% by weight of an ethylene-vinyl acetate copolymer, 20 to 50% by weight of an olefin-based elastomer and tackifying A glass bottle with a heat-sensitive label, comprising a heat-sensitive label having a heat-sensitive adhesive layer made of a heat-sensitive adhesive containing 10 to 30% by weight of the agent.   The glass bottle with a thermosensitive label according to claim 1, wherein the resin having a polar group is at least one resin selected from an acrylic resin, a urethane resin, and an epoxy resin.   The glass bottle with a heat-sensitive label according to claim 1 or 2, wherein the ethylene-vinyl acetate copolymer has an ethylene component content of 65 to 90 wt% and a vinyl acetate component content of 10 to 35 wt%.   The glass bottle with a heat-sensitive label according to any one of claims 1 to 3, wherein the olefin elastomer is an α-olefin copolymer elastomer.