JP2018052609A - Container and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a container having a resin layer that can be removed, extremely easily and efficiently, from the surface of the container body.SOLUTION: A container has a container body, an alkali soluble resin layer provided on the surface of the container body and containing an alkali-soluble resin, and a printed layer provided on the surface of the resin layer.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a container and a manufacturing method thereof, more specifically, a container including a container main body, an alkali-soluble resin layer, and a printing layer, and a manufacturing method thereof.

Conventionally, the surface of a container body filled with food or non-food has been provided with labels and resin layers (coating) printed with characters such as product names and designs, etc. Has been developed and proposed.
In recent years, the container body after use has been collected and reused from the viewpoints of environmental protection, resource saving, etc., and the peelability of the label and resin layer provided on the container body is required. Yes.

  For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2013-200191) proposes a container that has a knob and can peel and collect a label from a container body.

  However, the container proposed in Patent Document 1 may not be able to be peeled cleanly depending on the direction and force of pulling the label. Further, in this method, it is necessary to perform a peeling operation for each container, which is not efficient.

JP 2013-200491 A

  This invention is made | formed in view of such a condition, and is providing a container provided with the resin layer which can be peeled and removed very easily and efficiently from the surface of a container main body.

  The container of the present invention comprises a container main body, an alkali-soluble resin layer containing an alkali-soluble resin provided on the surface of the container main body, and a printed layer provided on the surface of the resin layer. And

  In the above embodiment, the alkali-soluble resin is preferably an alkali-soluble thermoplastic resin and / or an actinic ray curable resin.

  In the said aspect, it is preferable that the acid value of alkali-soluble resin is 100 mgKOH / g or more and 500 mgKOH / g or less.

  In the said aspect, it is preferable that a printing layer contains a coloring agent and alkali-soluble resin.

  In the said aspect, it is preferable to further provide a protective layer so that a printing layer may be covered.

  The container manufacturing method of the present invention includes a step of preparing a container body, a step of forming an alkali-soluble resin layer on the surface of the container body, and printing on the surface of the alkali-soluble resin layer, thereby printing And a step of forming a layer.

  The composition for forming an alkali-soluble resin layer of the present invention includes an alkali-soluble resin for forming an alkali-soluble resin layer provided in the container.

  The composition for forming a printed layer of the present invention is characterized by containing a colorant and an alkali-soluble resin for forming a printed layer provided in the container.

  According to the container of the present invention, the resin layer provided on the surface of the container body can be removed from the surface of the container body very easily and efficiently by impregnating with an alkaline solution.

FIG. 1 is a diagram illustrating a printed layer formed on a resin layer in an example.

(container)
The container of the present invention comprises a container main body, an alkali-soluble resin layer provided on the surface of the container main body, and a printed layer provided on the surface of the resin layer. In one embodiment, a protective layer may be provided so as to cover the printing layer.

(Container body)
The shape of the container main body used in the present invention is not particularly limited.
The material of the container body is not particularly limited, and a resin container, a glass container, a paper container, a metal container, or the like can be used.
When the container body is made of resin, the container is made of polyolefin resin such as polyethylene or polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene / vinyl alcohol copolymer, polyacrylonitrile, polyamide, acrylic ester or One or more kinds of resin materials such as acrylic resin mainly composed of methacrylic acid ester, polyester such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and polyacetal can be contained.
In addition to the resin materials described above, polyamide resins such as nylon-6, nylon-6,6 and MXD-6, homopolymers of vinyl chloride or vinylidene chloride, vinyl acetate, maleic acid derivatives, polyalkyl resins such as higher alkyl vinyl ethers, etc. A vinyl chloride resin, a polyacrylonitrile resin, a polyvinyl alcohol resin, and the like may be included.

  Moreover, the container main body may contain various additives in the range which does not impair the characteristic of this invention. Examples of additives include plasticizers, UV stabilizers, anti-coloring agents, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, yarn friction reducing agents, slip agents, mold release agents, Examples include oxidants, ion exchangers, dispersants, ultraviolet absorbers, and color pigments. As color pigments, pigments of various colors such as red, blue, yellow, green, brown, black, white, etc. can be used, but considering the ease of recycling, the container body is made of a color pigment. It is preferably not included.

  Corona discharge treatment, plasma treatment, ozone treatment, flame treatment, primer (also called anchor coat, adhesion promoter, or easy adhesive) coating treatment, pre-heat treatment, dust removal Surface treatment such as treatment, vapor deposition treatment, alkali treatment, and application of an antistatic layer is preferably performed.

(Alkali-soluble resin layer)
The container of the present invention includes an alkali-soluble resin layer (hereinafter, simply referred to as “resin layer” in some cases) provided on the surface of the container body.
In the present invention, “alkali-soluble” means that 0.1 g or more can be dissolved in an alkaline solution, for example, 100 mL of a 1.5 wt% aqueous sodium hydroxide solution at 85 ° C.

  In one embodiment, the resin layer may be provided on the entire container main body, or may be provided only at a location where the printing layer is to be formed.

The resin layer includes an alkali-soluble resin, and examples of the alkali-soluble resin include an alkali-soluble thermoplastic resin and an alkali-soluble actinic ray curable resin.
In the present invention, “active light” means radiation that chemically acts on the active light curable resin to promote polymerization, and specifically includes visible light, ultraviolet light, X-rays, electrons. It means a line, α ray, β ray, γ ray and the like.

As the alkali-soluble thermoplastic resin, those having a phenolic hydroxyl group and / or a carboxyl group in the main chain or side chain can be used.
For example, (meth) acrylic monomers such as (meth) acrylic acid esters and hydroxylethyl (meth) acrylate, nitrile monomers such as (meth) acrylonitrile, amide monomers such as (meth) acrylamide, N-amide monomers Alkoxy substituted products, N-methylol substituted products of amide monomers, styrene monomers such as styrene, vinyltoluene, α-methylstyrene, divinylbenzene, allyl monomers such as diallyl phthalate, allyl glycidyl ether, triallyl isocyanurate, acetic acid One or more monomers having a polymerizable double bond such as vinyl and N-vinylpyrrolidone, and (meth) acrylic acid, maleic acid, maleic anhydride, fumaric acid, tetrahydrophthalic anhydride having a carboxyl group , Itaconic acid One or more and is copolymerized with a copolymer of an unsaturated carboxylic acid of. Among these, a (meth) acrylic copolymer is particularly preferable.

  Alkali-soluble actinic ray curable resins are used as polymerization components such as 2-acryloyloxypropyltetrahydrophthalate, 2-acryloyloxypropylphthalate, 2-acryloyloxyethyltetrahydrophthalate, phenoxyethyl acrylate, N-vinylcaprolactam, cyclohexyl acrylate, tetrahydro Furfuryl acrylate, benzyl acrylate, methylphenoxyethyl acrylate, 4-t-butylcyclohexyl acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, tribromophenyl acrylate, ethoxylated tribromophenyl acrylate, 2-phenoxyethyl acrylate ethylene oxide, propylene oxide addition Monomer, acryloylmorpholine, pheno Sidiethylene glycol acrylate, vinyl caprolactam, vinyl pyrrolidone, 2-hydroxy-3-phenoxypropyl acrylate, 1,4-cyclohexanedimethanol monoacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, isobutyl acrylate , T-butyl acrylate, isooctyl acrylate, 2-methoxyethyl acrylate, methoxytriethylene glycol acrylate, 2-ethoxyethyl acrylate, 3-methoxybutyl acrylate, ethoxyethoxyethyl acrylate, butoxyethyl acrylate, ethoxydiethylene glycol acrylate, methoxydipropylene Glycol acrylate, dipropylene glycol Acrylate, β-carboxyl ethyl acrylate, ethyl diglycol acrylate, trimethylolpropane formal monoacrylate, imide acrylate, isoamyl acrylate, ethoxylated succinic acid acrylate, trifluoroethyl acrylate, ω-carboxypolycaprolactone monoacrylate, N-vinylformamide, etc. Monofunctional monomers, dimethylol-tricyclodecane diacrylate, propoxylated bisphenol A di (meth) acrylate, ethoxylated bisphenol A di (meth) acrylate, cyclohexanedimethanol di (meth) acrylate, dimethylol dicyclopentanedi Acrylate, ethoxylated isocyanuric acid triacrylate, tri (2-hydroxyethyl isocyanurate Triacrylate, tri (meth) allyl isocyanurate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, ethoxylated 1, 6-hexanediol diacrylate, neopentyl glycol di (meth) acrylate, polypropylene glycol diacrylate, 1,4-butanediol di (meth) acrylate, 1,9-nonanediol diacrylate, tetraethylene glycol diacrylate, 2- n-butyl-2-ethyl-1,3-propanediol diacrylate, neopentyl glycol diacrylate hydroxypivalate, 1,3-butylene glycol di (meth) acrylate , Trimethylolpropane triacrylate, hydroxypivalic acid trimethylolpropane triacrylate, ethoxylated phosphoric acid triacrylate, ethoxylated tripropylene glycol diacrylate, neopentyl glycol modified trimethylolpropane diacrylate, stearic acid modified pentaerythritol diacrylate, Pentaerythritol triacrylate, tetramethylolpropane triacrylate, tetramethylol methane triacrylate, pentaerythritol tetraacrylate, caprolactone-modified trimethylolpropane triacrylate, propoxylate glyceryl triacrylate, tetramethylol methane tetraacrylate, pentaerythritol tetraacrylate, ditrimethylol group Pantetraacrylate, ethoxylated pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, caprolactone-modified dipentaerythritol hexaacrylate, dipentaerythritol hydroxypentaacrylate, neopentyl glycol oligoacrylate, 1,4-butanediol oligoacrylate, 1,6 -Hexanediol oligoacrylate, trimethylolpropane oligoacrylate, pentaerythritol oligoacrylate, ethoxylated neopentyl glycol di (meth) acrylate, propoxylated neopentyl glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, ethoxylated Trimethylolpropane triacrylate, propoxylated A polyfunctional monomer such as trimethylolpropane triacrylate may contain one or more.

The acid value of the alkali-soluble resin is preferably 100 mgKOH / g or more and 500 mgKOH / g or less, and more preferably 150 mgKOH / g or more and 400 mgKOH / g or less. By making the acid value of the resin within the above numerical range, the peelability of the resin layer with an alkaline solution can be improved.
In the present invention, the “acid value” can be measured according to JIS K 0070.

  The resin layer preferably contains 5% by mass or more and 80% by mass or less of an alkali-soluble resin, and more preferably contains 10% by mass or more and 50% by mass or less.

  The resin layer may contain a resin other than the alkali-soluble resin as long as the characteristics are not impaired. For example, polyester resins, vinyl resins, fluorine resins, styrene resins, (meth) acrylic resins, cellulose resins, carbonate resins, amide resins, polyolefin resins such as propylene resins, vinyl alcohol resins, Examples include imide resins, phenol resins, and urethane resins.

When an alkali-soluble actinic ray curable resin is used as the resin layer, a polymerization initiator may be included as necessary. The polymerization initiator may be a photopolymerization initiator (an initiator when using light or electron beam irradiation) or a thermal polymerization initiator (an initiator when using a thermal polymerization reaction). .
As photopolymerization initiators, trimethylamine, methyldimethanolamine, triethanolamine, p-diethylaminoacetophenone, ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, N, N-dimethylbenzylamine and 4,4 And '-bis (diethylamino) benzophenone.
Examples of the thermal polymerization initiator include 2,2′-azobisisobutylnitrile, 2,2′-azobis-2-methylbutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2 , 2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 1,1′-azobis-1-cyclohexylnitrile, dimethyl-2,2′-azobisisobutyrate, 4,4′-azobis -4-Cyanobarelic acid and the like.

  The resin layer may contain various additives as long as the characteristics are not impaired. Examples of additives include colorants such as pigments and dyes, plasticizers, pH adjusters, UV stabilizers, anti-coloring agents, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, yarns Examples thereof include a friction reducing agent, a slip agent, a release agent, an antioxidant, an ion exchange agent, and a coloring pigment.

  The thickness of the resin layer is preferably 0.1 μm or more and 50 μm or less, and more preferably 1 μm or more and 20 μm or less.

(Print layer)
The container of the present invention comprises a printed layer on which characters, figures, symbols, patterns, etc. are printed on the surface of an alkali-soluble resin layer. Thus, by providing the printing layer on the alkali-soluble resin layer, it can be removed from the surface of the container body together with the removal of the resin layer.

  The printed layer can comprise a colorant. The colorant may be a dye or a pigment, and various colorants such as red, blue, yellow, green, brown, black, and white can be used.

The printed layer is made of polyester resin, polycarbonate resin, polyacrylic resin, polyurethane resin, polyamide resin, polyvinyl resin, silicone-modified resin of these resins, UV-absorbing resin, alkali-soluble resins described above, and the like. 1 type or 2 types or more of resin compositions, such as a mixture of these, can be included.
Among these, alkali-soluble resins are preferable because they can be easily removed when the resin layer is removed.

  In the case where an alkali-soluble actinic ray curable resin is used as the printing layer, a polymerization initiator as described above may be included as necessary.

  In addition, the printing layer can contain a pH adjuster, a preservative, a fungicide, a chelating agent, a plasticizer, an antioxidant, and the like.

(Protective layer)
The protective layer is a layer that is provided as desired, and is a layer that covers the print layer and protects the print layer.
In one embodiment, the protective layer may be provided over the entire surface of the container main body, or may be provided only at a location where the printing layer is provided.

  The protective layer preferably comprises a thermosetting resin or an actinic ray curable resin, and an actinic ray curable resin is more preferred from the viewpoint of high surface hardness and excellent productivity. A thermosetting resin and an actinic ray curable resin may be used in combination.

As the actinic ray curable resin, those described above can be used.
Examples of the thermosetting resin include phenol resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, aminoalkyd resin, melamine-urea cocondensation resin, silicon Examples thereof include resins and polysiloxane resins. Furthermore, it is preferable to use these resins in combination with a thermal polymerization initiator, a curing accelerator, a curing agent, and the like.

  The thickness of the protective layer is preferably 0.1 μm or more and 50 μm or less, and more preferably 1 μm or more and 30 μm or less.

(Manufacturing method of container)
The method for producing a container of the present invention comprises a step of preparing a container body, a step of providing an alkali-soluble resin layer on the surface of the container body, and printing on the surface of the alkali-soluble resin layer to thereby form a printed layer. And forming. Moreover, the process of providing a protective layer so that a printing layer may be covered is included if desired.
Hereinafter, each step will be described.

(Process of preparing the container body)
As described above, the container body may be any of a resin container, a glass container, a paper container, and a metal container, and these container bodies can be manufactured by a conventionally known method. Moreover, you may use the container main body marketed.
For example, when the container body is made of resin, it can be produced by a molding method such as a T-die method, an inflation method, an injection molding method, or a blow molding method.

(Step of forming an alkali-soluble resin layer)
In one embodiment, the alkali-soluble resin layer is prepared by adding a mixture containing the above-described alkali-soluble resin or the like to an appropriate solvent as necessary to obtain a composition for forming an alkali-soluble resin layer. By this method, it can be formed by applying and drying on the container body. Examples of the coating method include a gravure coating method, a roll coating method, a comma coating method, a gravure printing method, a screen printing method, an ink jet printing method, and a gravure reverse roll coating method.
The solvent that can be used is not particularly limited, but water, methanol, ethanol, propanol, isopropyl alcohol, ethyl acetate, butyl acetate, acetone, dimethyl ketone, methyl ethyl ketone, toluene, butylhydroxytoluene, hexane, xylene Etc. can be used.
Moreover, when comprising actinic-light curable resin, a resin layer can be formed by irradiating actinic light after apply | coating the composition for alkali-soluble resin layer formation.

(Process of forming the printing layer)
The printing layer is obtained by subjecting the above-mentioned colorant, resin composition, and the like and a composition for forming a printing layer containing a solvent to a resin layer by a known printing method such as an offset printing method, a gravure printing method, and an inkjet printing method. It can be formed by coating on top and drying. As the solvent that can be used, the same solvents as those that can be used for forming the resin layer can be used.
When the actinic ray curable resin is contained, the printing layer can be formed by irradiating actinic rays after applying the composition for forming a printing layer.

(Step of forming a protective layer)
The protective layer comprises the above-described resin composition and the like and a protective layer-forming composition containing a solvent, if desired, by a known printing method such as an offset printing method, a gravure printing method, an inkjet printing method, and the like. It can form by apply | coating on a resin layer and drying. As the solvent that can be used, the same solvents as those that can be used for forming the resin layer can be used.
When comprising actinic ray curable resin, a protective layer can be formed by irradiating actinic rays after apply | coating the composition for protective layer formation.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.

<Example 1>
(Process of preparing the container body)
A PET bottle was prepared.

(Step of forming an alkali-soluble resin layer)
A resin layer forming composition having the following composition was applied to one surface of a bottle by a gravure printing method and then dried to form a resin layer. The thickness of the resin layer was 2 μm.
<Composition of resin layer forming composition>
-15 parts by mass of a styrene-maleic anhydride copolymer (acid value: 270 mg KOH / g, manufactured by Kawa Crude Chemical Co., Ltd., trade name: SMA17352P)
・ Acrylic resin 4 parts by mass (acid value: 4 mg KOH / g, manufactured by Toagosei Co., Ltd., trade name: UH2011)
Cellulose-based resin 1 part by mass (trade name: CAB-381-0.5, manufactured by Eastman Chemical Co., Ltd.)
-50 parts by mass of ethyl acetate-30 parts by mass of isopropyl alcohol

(Process of forming the printing layer)
A composition for forming a printing layer having the following composition is discharged onto a resin layer by an ink jet printing method, and then an ultraviolet irradiation device (Harrison Toshiba Lighting, lamp output: 120 W / cm, one high-pressure mercury lamp, Irradiation distance: 10 cm, conveyor speed: 5 m / min, 1 Pass) was used to irradiate ultraviolet rays to form a printed layer composed of characters shown in FIG. 1 to obtain a container. The thickness of the printing layer was 1 μm.
<Composition of printing layer forming composition>
Pigment dispersion 10 parts by mass (pigment dispersant (manufactured by Lubrisol, trade name: Solspers 32000) 35 parts by mass, phenoxyethyl acrylate 61 parts by mass)
-Phenoxyethyl acrylate 65 parts by mass-N-vinylcaprolactam 17 parts by mass-Neopentyl glycol-modified trimethylolpropane diacrylate 8 parts by mass-Polymerization initiator A 5 parts by mass (product name: Irgacure 907)
Polymerization initiator B 5 parts by mass (Ciba Specialty Chemicals, trade name: Irgacure 819)
・ Butylhydroxytoluene 1 part by mass

<Example 2>
The composition of the resin layer forming composition was changed as follows, and this coating solution was applied to one surface of the bottle by a gravure printing method, and then an ultraviolet irradiation device (Harison Toshiba Lighting Co., Ltd., lamp output: 120 W / cm, one high-pressure mercury lamp, irradiation distance: 10 cm, conveyor speed: 5 m / min. 1 Pass), and using the same method as in Example 1 except that the resin layer was formed by irradiation with ultraviolet rays. A container was prepared.
<Composition of resin layer forming composition>
-70 parts by mass of 2-acryloyloxypropyltetrahydrophthalate-20 parts by mass of pentaerythritol tetraacrylate-5 parts by mass of lauryl acrylate-5 parts by mass of tridecyl acrylate-Oligo {2-hydroxy-2-methyl-1- [4- (1 -Methylvinyl) phenyl] propanone} 2.8 parts by mass (trade name: Ezacure KIP150, manufactured by Rambach)
・ 0.3 parts by mass of perfluoroalkyl group / lipophilic group-containing oligomer (manufactured by Dainippon Ink & Chemicals, Inc., trade name: MegaFuck F-173)

<Peel test>
The following peel test was performed on the container obtained as described above.
The containers obtained in Examples 1 and 2 were immersed in a 1.5 wt% sodium hydroxide aqueous solution at 85 ° C., and the detached state of the alkali-soluble resin layer and the printing layer was observed while the aqueous solution was simply stirred. did. Specifically, the time (minutes) during which the alkali-soluble resin layer and the printing layer spontaneously drop off (naturally during immersion without removing the printed resin plate after immersion and exposing it to water or rubbing). ) And the peelability was evaluated according to the following evaluation criteria. The evaluation results are shown in Table 1.
Evaluation standard ( circle): Time to drop off almost completely is less than 20 minutes.
X: The time to drop off almost completely is 20 minutes or more.

Claims (8)

  A container comprising: a container body; an alkali-soluble resin layer including an alkali-soluble resin provided on a surface of the container body; and a printed layer provided on a surface of the resin layer.   The container according to claim 1, wherein the alkali-soluble resin is an alkali-soluble thermoplastic resin and / or an actinic ray curable resin.   The container according to claim 1 or 2, wherein an acid value of the alkali-soluble resin is 100 mgKOH / g or more and 500 mgKOH / g or less.   The container according to any one of claims 1 to 3, wherein the printed layer comprises a colorant and an alkali-soluble resin.   The container according to any one of claims 1 to 4, further comprising a protective layer so as to cover the printed layer. Preparing the container body;
Forming an alkali-soluble resin layer on the surface of the container body;
And a step of forming a printed layer by printing on the surface of the alkali-soluble resin layer.   The composition for alkali-soluble resin layer formation containing the alkali-soluble resin used in order to form the alkali-soluble resin layer with which the container as described in any one of Claims 1-5 is equipped.   A composition for forming a printing layer, comprising a colorant and an alkali-soluble resin, which is used for forming the printing layer according to claim 4.

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