WO2011070685A1 - Light-blocking silver ink composition and packaging containing using same - Google Patents
Light-blocking silver ink composition and packaging containing using same Download PDFInfo
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- WO2011070685A1 WO2011070685A1 PCT/JP2009/070798 JP2009070798W WO2011070685A1 WO 2011070685 A1 WO2011070685 A1 WO 2011070685A1 JP 2009070798 W JP2009070798 W JP 2009070798W WO 2011070685 A1 WO2011070685 A1 WO 2011070685A1
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- light
- silver ink
- shielding
- printing
- ink composition
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D11/00—Inks
- C09D11/02—Printing inks
- C09D11/10—Printing inks based on artificial resins
- C09D11/102—Printing inks based on artificial resins containing macromolecular compounds obtained by reactions other than those only involving unsaturated carbon-to-carbon bonds
- C09D11/104—Polyesters
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
- C09D5/32—Radiation-absorbing paints
Definitions
- the present invention relates to a packaging material and a silver ink composition for printing (hereinafter referred to as “silver ink”) capable of imparting light shielding properties to a packaging container using the packaging material and a paper container using the silver ink. More specifically, a silver ink suitable for gravure printing that can impart light-shielding properties by printing on a beverage paper container whose quality is altered by light, etc., and a wrapping paper container using this silver ink About.
- Paper packaging containers are widely used.
- milk and juice are supplied to the market in a so-called roof-type paper pack container (gable top type) and are widely spread. Since these containers have a structure in which an extremely thin synthetic resin layer is laminated on a thin paperboard, the rate of transmitting light is high.
- the paper pack container is exposed to strong light for a long time by sunlight, indoor lighting in a store, and fluorescent lighting of a showcase during the distribution process.
- Patent Literature For example, a paper pack container is proposed in which a light-shielding printing layer made of an ink containing a carbon black pigment is provided between the base material of the packaging material and the innermost layer, and a colored printing layer located inside the light-shielding printing layer. (See Patent Document 1).
- a paper pack container having a configuration in which a design layer, a white print layer, a light-shielding color print layer are provided from the outside and a thermoplastic resin layer is provided as the innermost layer on the outside of the paper layer of the base material with a packaging material not containing aluminum foil
- a packaging material has been proposed (see Patent Document 2).
- a light-shielding printing layer is provided on the surface of the packaging material with an ink containing an aluminum paste pigment and polyethylene wax (see Patent Document 3). This relates to the proposal of one of the applicants of the present invention, and the present invention further improves this.
- Patent Document 1 light-shielding printing with black ink containing carbon black (see Patent Document 1) exhibits an excellent effect on light-shielding properties, but the design of printing applied over this layer due to the influence of the black color of the base. There is a defect that the property becomes worse (the dullness etc. appears and the design printing does not finish cleanly).
- the silver inks disclosed in Patent Documents 3 and 4 are obtained by converting an aluminum pigment into an ink.
- the light shielding is excellent by a very simple means of printing on a packaging material and a packaging container using the packaging material, particularly a paper pack container.
- the printed layer has excellent adhesion and friction resistance, and resists rubbing during transportation. , And has excellent characteristics such as long-lasting light shielding properties.
- the silver ink is suitable for gravure printing, and it is necessary to print the silver ink solidly in order to impart light shielding properties to the packaging material.
- the printing speed is set to 100 to 150 m / min.
- gravure printing at a printing speed of 150 m / min and gravure printing on the same speed could be carried out without any problem.
- the present invention is a gravure printing silver ink capable of high speed printing equivalent to offset printing, and further a gravure printing silver ink capable of UV offset printing at the same speed and a packaging container using the silver ink It is an issue to provide.
- the inventors have solved the above problems by improving silver ink and completed the present invention. That is, it is necessary to improve the adhesion of the gravure printing silver ink to be the base printing and the adhesion to the UV offset printing to be superimposed on the base printing. Therefore, the present inventors have used a combination of two types of polyester resins having different glass transition points instead of the combination of nitrified cotton and polyester resin used as a binder in the silver ink described in Patent Document 4. The said subject was solved.
- the silver ink of the present invention does not have insufficient printing density or blur even in gravure printing at 300 m / min, and no problem occurs even when UV offset printing (design printing) is performed at the same printing speed. There wasn't. That is, since the printing speeds of gravure printing and UV offset printing are the same, both of them can be continuously printed, and the printing speed is almost doubled, so that the productivity can be greatly improved. That is, a light-shielding silver ink composition containing 60 to 100 parts by weight of an aluminum pigment with respect to 100 parts by weight of a polyester resin, wherein the polyester resin has a glass transition point of ⁇ 20 to 10 ° C. and a number average molecular weight of 5000.
- a light-shielding printing layer is provided on the surface of the laminated packaging material provided with a synthetic resin layer on each of the upper surface and the lower surface of the paperboard substrate using a light-shielding silver ink composition, and the light-shielding printing It is a light-shielding packaging material in which a design printing layer is provided on the layer, and is a packaging container made from the light-shielding packaging material described above.
- a black pigment such as carbon black is not included, a high-brightness silver-colored light-shielding printing layer can be formed, and even if design printing is performed thereon, the base does not affect the design printing. It is possible to print design of any color by printing. Since the silver ink of the present invention can perform gravure printing at a printing speed of 300 m / min, which is a printing speed normally used in offset printing, after gravure printing with silver ink, design printing by UV offset can be continuously performed on the same line. Become. In other words, when the silver ink of the present invention is used, the conventional gravure printing speed is about 150 m / min. However, gravure printing and UV offset printing can be carried out continuously at 300 m / min.
- the silver ink of the present invention does not cause a decrease in ink density even when gravure printing is performed at a high speed, and printing blur does not occur. Furthermore, even if design printing is performed on the silver ink printing layer, the design printing does not come into close contact with the silver ink printing layer and peel off. Of course, since there is little odor, the taste and smell of the contents of the packaging container are not changed.
- the ink of the present invention has significantly improved adhesion to offset UV (photocuring) ink, so there is no need to provide a curing time until the next overprinting. For example, a gravure printing unit in an offset printing machine Etc., printing can be performed in a consistent flow operation, the installation area of the equipment can be reduced, and workability has been remarkably improved.
- the light transmission blocking rate is comparable to the conventional one.
- FIG. 1 shows a case in which a light-shielding printing layer is provided by solid printing with the silver ink described in Example 3 on a packaging material substrate described in a comparative test example.
- FIG. 2 shows a black base printed on a packaging material base material described in the comparative test example with LRC-NT910 ink manufactured by Tokyo Ink Co., Ltd.
- the packaging container of the present invention is obtained by solid-printing the silver ink of the present invention on a portion of a laminated packaging material (packaging material substrate) having a synthetic resin layer on the inner surface and outer surface of the paperboard substrate that requires light shielding. (Light-shielding imparted print layer), a design print layer is further provided thereon, and this is molded and assembled into a paper pack container.
- polyester resins are used as binders.
- One is a polyester resin having a glass transition point (Tg) of ⁇ 20 to 10 ° C., a number average molecular weight of 5000 to 25000 and a hydroxyl value of 5 to 20, and the other is a glass transition point (Tg) of 30 to 100 ° C.
- a polyester resin having an average molecular weight of 5000 to 25000 and a hydroxyl value of 5 to 20 By combining these polyester resins having a low glass transition point and polyester resins having a high glass transition point, the printing density does not decrease even in high-speed printing at 300 m / min, and the adhesiveness to the packaging material substrate is excellent.
- polyester resins are 1/1 to 11/1 by weight (polyester resin having a low glass transition point / polyester resin having a high glass transition point). If this mixing ratio exceeds 11/1, it cannot be used substantially because of blocking, and if this ratio is less than 1/1, the adhesion to the packaging material substrate and UV offset printing becomes insufficient. In addition, adhesiveness and blocking resistance could not be made compatible with only one type of polyester resin.
- the aluminum pigment used in the silver ink of the present invention is non-leafing type aluminum having an average particle diameter of 5 to 15 ⁇ m and is dispersed in n-propyl acetate.
- the average particle size of the aluminum pigment is less than 5 ⁇ m, not only the brightness is greatly reduced and the design property is lacking, but also the adhesion of the ink film is lowered, and the aluminum pigment is easily peeled off.
- the average particle diameter is a measured value by a laser method (manufactured by MICROTRAC 9320 ⁇ 100 Honeywell).
- Leafing type aluminum pigments are easy to achieve high brightness and excellent in concealment properties, but they float on the surface when printed, and therefore have poor friction resistance and ink film adhesion.
- the non-leafing type since the non-leafing type has the property of being randomly dispersed in the ink film, the resin used for the ink material is likely to enter between the thin aluminum pigments.
- the addition amount of the aluminum pigment is 60 to 100 parts by weight with respect to 100 parts by weight of the polyester resin. If the amount of the aluminum pigment added is less than 60 parts by weight, the brightness is lowered, so that the printed material lacks design properties, and the light shielding property of the printed material becomes insufficient. On the other hand, when the amount exceeds 100 parts by weight, it is not preferable because plate clogging, two-to-stain, etc. are likely to occur and the adhesiveness is lowered. In the silver ink of the present invention, it is preferable to add a wax in order to improve the friction resistance.
- wax to be used examples include polyethylene wax, polypropylene wax, poly (ethylene-propylene) copolymer wax, carbana wax, paraffin wax, microcrystalline wax, candelilla wax, white wax and the like, but having a weight average molecular weight of 1,000 to 5,000.
- Polyethylene wax is particularly preferably used, and the amount added is 2 to 10 parts by weight with respect to 100 parts by weight of the polyester resin.
- the overcoat layer on the printed surface especially when no wax is added to the silver ink, improves the abrasion resistance by overcoating on the light-shielding printing and design printing with silver ink. It is preferable to provide it.
- This overcoat layer is made of polyethylene resin, polypropylene resin, ethylene-vinyl acetate resin, ethylene-ethyl acrylate resin, acetate nitrocellulose resin, nitrocellulose resin, polyamide resin, acrylic resin, polyurethane resin. , Polyester resins, epoxy resins, silicon resins, fluorine resins, etc., and those resins with fillers, lubricants, UV absorbers, antioxidants, water repellents, oil repellents, etc. It can form by apply
- the addition amount of the polyisocyanate is preferably 1 to 10 parts by weight with respect to 100 parts by weight of the polyester resin, and the type thereof is not particularly limited, but a non-yellowing type polyisocyanate is preferably used.
- the silver ink of this invention was demonstrated as a composition except a solvent, all the raw materials used for the silver ink of this invention have used what was melt
- polyester resins two types are those in which about 30% by weight is dissolved in a mixed solvent of ethyl acetate and methyl ethyl ketone, polyethylene wax is about 25% by weight dispersed in isopropyl alcohol, and aluminum pigment is n-acetate.
- solvents are appropriately selected according to the source and solubility of the raw materials, and the concentration thereof is also determined as appropriate.
- ester solvents and / or ketone solvents are used.
- those having a lower carbon number of 3 to 6 are preferably used.
- a small amount of a low-alcohol solvent can be used, but the polyester resin used in the present invention cannot be used in a large amount because of its low solubility in a low-alcohol solvent.
- an organic solvent for concentration adjustment is used in order to maintain its quality maintenance and stability, or to adjust the viscosity to be suitable for printing.
- ester solvents and / or ketone solvents particularly those having a lower carbon number of 3 to 6 are preferably used.
- the silver ink of the present invention is prepared by mixing the raw materials described above, that is, two types of polyester resin and an aluminum pigment, and, in some cases, a wax and a polyisocyanate, and adding a concentration adjusting solvent to the mixture. Manufactured. Furthermore, you may use the well-known adjuvant used for the printing ink as needed for the silver ink of this invention. For example, a plasticizer, a leveling agent, a surfactant, a dispersant, an antifoaming agent, etc. may be used. With the above configuration, the silver ink of the present invention has improved adhesion to the packaging material base material and the UV offset ink, and the silver ink printing and the offset printing performed successively are used in normal offset printing.
- the silver ink of the present invention is suitable for gravure printing and has high-speed printing suitability.
- the thickness of the light-shielding printing layer using the silver ink of the present invention is preferably 1 to 10 ⁇ m. If the thickness is less than 1 ⁇ m, the light-shielding effect is insufficient, and if it exceeds 10 ⁇ m, not only is it practically excessive, but the cost is increased.
- UV offset printing can be performed on the surface printed with the silver ink of the present invention, and the printing method is based on the usual method of UV offset printing. No special equipment is required for its use.
- Example 1 50 parts of polyester resin Byron 500 (manufactured by Toyobo Co., Ltd.), 10 parts of polyester resin Byron 103 (manufactured by Toyobo Co., Ltd.), 4 parts of polyethylene wax HY-04 (manufactured by Mitsui Chemicals) and non-leafing type 20 parts of aluminum pigment CS430YC (manufactured by Showa Aluminum Powder Co., Ltd.) was mixed, and 16 parts of ethyl acetate was further added to obtain 100 parts of silver ink.
- Examples 2 and 3 In the same manner as in Example 1, mixing was performed according to the composition shown in Table 1 to obtain a silver ink. Comparative Examples 1-4 As in Example 1, silver ink was obtained by mixing according to the composition shown in Table 2.
- the various physical properties of the raw materials listed in Tables 1 and 2 were measured by the following methods. 1.
- the average particle diameter of the aluminum pigment is a value measured by a laser particle size distribution analyzer (MICROTRAC 9320-X100 manufactured by Honeywell). 2.
- Glass transition point (polyester resin) Differential scanning calorimetry This is a value measured by DSC under the conditions of 5 mg of sample, measurement temperature of ⁇ 60 to 120 ° C., and heating rate of 20 ° C./min. 3.
- a UV offset printing packaging material sample was prepared, and a comparative test was performed and evaluated for each of the items of friction resistance, water friction resistance, adhesion (raw fabric), UV ink adhesion, color development, and odor.
- a packaging material base material a commercially available roll paper made by Straenso, Finland (width 587 mm ⁇ length 4000 mm ⁇ thickness 0.43 mm, outer surface thermoplastic resin layer having a thickness of 0.017 mm on the upper surface and thickness on the lower surface Prepared with a 0.027 mm inner surface thermoplastic resin layer), and seven types of inks of each constitution were used for this packaging material base, and the printing speed was 300 m per minute with a solid thickness of about 3 ⁇ m.
- a solid print packaging material was created by gravure printing.
- UV offset ink (FD Carton ACE ink, manufactured by Toyo Ink Co., Ltd.) was printed at a printing speed of 300 m / min on each of the seven types of solid printing packaging materials prepared in [Preparation of solid printing packaging material].
- a UV offset printing packaging material was prepared.
- [Comparative test] (1), (2) Friction resistance and water rub resistance test For the seven types of solid printing packaging materials obtained in [Preparation of solid printing packaging materials] Using a testing machine FR-II, manufactured by Suga Test Instruments Co., Ltd.), a 50-stroke friction test was performed with a load of 500 g in accordance with JIS-P8136.
- the light transmittance is measured. At a wavelength where the transmittance of visible light is maximum, the transmittance is less than 3%, 5 is 3 to 4%, 4 is 4 to 5%, and 3 and 5 is the case.
- the case of ⁇ 7% was evaluated as 2, and the case of 7% or more was evaluated as 1.
- Odor Three panelists evaluated the smell of the seven solid print packaging materials obtained in [Preparation of solid print packaging material], but almost all of the examples and comparative examples were odorous. Was not felt.
- the test results are summarized in Table 3, but solid printing packaging materials are used for friction resistance, water friction resistance, adhesion (raw fabric) and color development (during high-speed printing), and UV ink adhesion is UV offset. It is evaluated using a printing packaging material.
- Test example 1 The following samples were prepared, light was irradiated from the printed layer side, and a comparative test of the light transmittance was performed.
- the following test samples were prepared using the same packaging material substrates described in the comparative test examples.
- Sample A The silver ink described in Example 3 was used for the packaging material base material, and solid printing was performed at a speed of 300 m / min in the same manner as in [Preparation of solid printing packaging material]. In addition, a printable printing layer is provided.
- Sample B LRC-NT910 black manufactured by Tokyo Ink Co., Ltd.
- Light transmittance Samples A and B were measured using a V-670 type ultraviolet-visible spectrophotometer manufactured by JASCO Corporation.
- Optical system Single monochromator Zernita mount, double beam system
- Light source Deuterium lamp (190-350nm), Halogen lamp (330-2700nm)
- Wavelength range 190-2700nm (Spectral bandwidth 0.5nm, UV-visible region)
- the so-called visible light is in the range of 400 to 800 nm, and was measured including before and after that range.
- the measurement wavelength range is 190 to 2700 nm, and the spectral bandwidth is 0.5 nm.
- the measurement result is shown. (Fig. 1) (Fig. 2) It is shown that the lower the light transmittance, the higher the light shielding effect as a sample packaging material. It can be seen that Sample A has a light-shielding effect comparable to that printed on black (Sample B). It can be evaluated as an effect that can sufficiently withstand practical use. Test example 2 The sample of the following conditions was made, the sensory test of this was performed, and the light shielding effect evaluation test was done.
- Example 1 Using a silver ink as described in Example 3 above, a 1 liter paper pack container (roof type) is created from the solid printing packaging material prepared according to [Creation of solid printing packaging material] This was filled with non-adjusted milk and sealed.
- Sample 2 A commercially available standard 1 liter paper pack container (roof-type type, without light-shielding printing) was prepared, and this was filled with non-adjusted milk and sealed. All samples were filled and sealed under the same conditions at the same time. (Test conditions) This milk-containing sealed container was stored in a store window refrigerator for one week, and whether or not the flavor had changed was evaluated by a sensory test.
- the temperature inside the refrigerator during storage was 4 to 8 ° C., and the store and the fluorescent lamps in the show window were continuously irradiated.
- the sample was returned to room temperature and evaluated by 4 panelists (experts with special training in taste discrimination). (Evaluation methods)
- the test method was based on the SD method (semantic differential method).
- the SD method is an abbreviation for Semantic Differential Method, but it can describe sample characteristics and images from various angles. For example, 10 to 30 items are used on a 5- to 7-level evaluation scale in which the opposite words such as refined-vulgar, feminine-masculine, dark-light, etc. are placed on both poles.
- the panel is marked for each characteristic or image item on the corresponding scale position (survey sheet).
- An average value of evaluations obtained as numerical values can be obtained and plotted on a scale to draw a profile of each sample.
- multivariate analysis such as principal component analysis and factor analysis is often used.
- the following (1) to (8) sensory evaluation question items were scored in the range of 3 to -3, and the evaluation was obtained.
- (1) Overall preference (2) Good or bad taste (3) Good or bad smell in the mouth (4) Good or bad throat (5) Sweetness (6) Presence or absence of freshness (7) Presence or absence of richness (8) Good aftertaste
- the evaluation score is based on the following scale.
- Sample 1 showed a significant difference in (1) overall preference compared to the other samples.
- sample 1 is high in each of the following items: (2) good and bad taste, (3) good and bad smell in mouth, (4) good and bad throat, (6) freshness and (8) good aftertaste Evaluation was accepted.
- the evaluation of Sample 1 was low because it is considered that “the milky ingredient is separated due to light degradation, and the richness is increased”. It is considered that the effect of suppressing the above was confirmed.
- the packaging container according to the present invention does not react to the metal detector, so that it can be confirmed that it does not hinder the detection of metal foreign objects that should react with the metal detector.
- the metal detector used is K112127 manufactured by Anritsu Corporation. The detection accuracy was performed with an iron ball of 1.5 ⁇ and a SUS ball of 3.0 ⁇ .
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Abstract
In order to obtain a silver ink that, in forming a printing layer that has been granted light-blocking properties due to the silver ink, allows high-speed printing and has excellent adhesion to a UV (photo-cured) offset ink, even if design printing is performed following gravure printing that uses the silver ink, a mixture of two polyester resins having differing glass transition points is used instead of the heretofore known mixture of a polyester resin and nitrocellulose used as a binder in the silver ink.
Description
本発明は、包装材料及びこれを使用した包装容器に遮光性を付与することができる印刷用の銀インキ組成物（以下「銀インキ」という。）並びに当該銀インキを使用した紙容器に関する。さらに詳しくは、光によってその品質に変質等を来す飲料用紙製容器に印刷を施すことにより、遮光性を付与することのできるグラビア印刷に適した銀インキ及びこの銀インキを使用した包装用紙容器に関する。
The present invention relates to a packaging material and a silver ink composition for printing (hereinafter referred to as “silver ink”) capable of imparting light shielding properties to a packaging container using the packaging material and a paper container using the silver ink. More specifically, a silver ink suitable for gravure printing that can impart light-shielding properties by printing on a beverage paper container whose quality is altered by light, etc., and a wrapping paper container using this silver ink About.
近年、牛乳、ジュース等の飲料は、コストの有利性及びその利便性が評価されて、板紙を主体とし、これに極薄い合成樹脂層を複数層積層した構造の包装材基材から作成された紙製包装容器（以下「紙パック容器」という。）が広く使用されている。
例えば、牛乳、ジュース等は、いわゆる屋根型の紙パック容器（ゲーブルトップ型）で市場に供給され、広く普及している。
これらの容器は、薄い板紙に極薄い合成樹脂層が積層された構造を持つことから、光を透過する率が高い。
前記の紙パック容器は、流通過程で日光、店舗内での室内照明、ショーケースの蛍光灯照明で、強い光に長時間晒される。その結果、内容物の性質によっては、強い光の影響を受け、品質の劣化又は変質等を惹起する場合が、少なからずある。
この光透過による内容物の変質・劣化等を防止するため、遮光層を設けた紙パック容器が提案されている。
［先行技術文献］
［特許文献］
例えば、包装材の基材と最内層との間にカーボンブラック顔料を含むインキからなる遮光性印刷層と、前記遮光性印刷層の内側に位置する着色印刷層を設けた紙パック容器が提案されている（特許文献１参照）。
また、アルミニウム箔を含まない包装材料で基材の紙層の外側に、外側からデザイン層、白色印刷層、遮光色印刷層を設け、最内層に熱可塑性樹脂層を配した構成の紙パック容器の包装材が提案されている（特許文献２参照）。
さらに、包装材の表面にアルミペースト顔料、及びポリエチレンワックスを含有させたインキで遮光印刷層を設けた提案がある（特許文献３参照）。
これは、本発明の出願人の内の１人の提案に係るものであり、本発明はさらにこれを改良したものである。
その他、低沸点エステル系溶剤／又は低沸点アルコール系溶剤に分散したノンリーフィングタイプのアルミニウムペースト、ポリエチレンワックス及びシリカを含有するインキで遮光印刷層を設けたものが提案されている（特許文献４参照）。
これは、本発明の出願人の内の１人の提案に係るものであり、本発明はさらにこれを改良したものである。
特開平７−５２３２８号公報
特開２００２−２５５１５８号公報
特開２００７−２３０２００号公報
特開２００９−５１９０３号公報
In recent years, beverages such as milk and juice have been evaluated from the advantages of cost and convenience, and have been made from a packaging material base material with a structure in which multiple layers of ultra-thin synthetic resin layers are laminated mainly on paperboard. Paper packaging containers (hereinafter referred to as “paper pack containers”) are widely used.
For example, milk and juice are supplied to the market in a so-called roof-type paper pack container (gable top type) and are widely spread.
Since these containers have a structure in which an extremely thin synthetic resin layer is laminated on a thin paperboard, the rate of transmitting light is high.
The paper pack container is exposed to strong light for a long time by sunlight, indoor lighting in a store, and fluorescent lighting of a showcase during the distribution process. As a result, depending on the nature of the contents, there are not a few cases where it is affected by strong light and causes quality degradation or alteration.
In order to prevent the deterioration and deterioration of the contents due to the light transmission, a paper pack container provided with a light shielding layer has been proposed.
[Prior art documents]
[Patent Literature]
For example, a paper pack container is proposed in which a light-shielding printing layer made of an ink containing a carbon black pigment is provided between the base material of the packaging material and the innermost layer, and a colored printing layer located inside the light-shielding printing layer. (See Patent Document 1).
In addition, a paper pack container having a configuration in which a design layer, a white print layer, a light-shielding color print layer are provided from the outside and a thermoplastic resin layer is provided as the innermost layer on the outside of the paper layer of the base material with a packaging material not containing aluminum foil A packaging material has been proposed (see Patent Document 2).
Furthermore, there is a proposal in which a light-shielding printing layer is provided on the surface of the packaging material with an ink containing an aluminum paste pigment and polyethylene wax (see Patent Document 3).
This relates to the proposal of one of the applicants of the present invention, and the present invention further improves this.
In addition, a non-leafing type aluminum paste dispersed in a low-boiling ester solvent / or a low-boiling alcohol solvent, an ink containing polyethylene wax and silica provided with a light-shielding printing layer has been proposed (see Patent Document 4). ).
This relates to the proposal of one of the applicants of the present invention, and the present invention further improves this.
JP 7-52328 A JP 2002-255158 A JP 2007-230200 A JP 2009-51903 A
例えば、牛乳、ジュース等は、いわゆる屋根型の紙パック容器（ゲーブルトップ型）で市場に供給され、広く普及している。
これらの容器は、薄い板紙に極薄い合成樹脂層が積層された構造を持つことから、光を透過する率が高い。
前記の紙パック容器は、流通過程で日光、店舗内での室内照明、ショーケースの蛍光灯照明で、強い光に長時間晒される。その結果、内容物の性質によっては、強い光の影響を受け、品質の劣化又は変質等を惹起する場合が、少なからずある。
この光透過による内容物の変質・劣化等を防止するため、遮光層を設けた紙パック容器が提案されている。
［先行技術文献］
［特許文献］
例えば、包装材の基材と最内層との間にカーボンブラック顔料を含むインキからなる遮光性印刷層と、前記遮光性印刷層の内側に位置する着色印刷層を設けた紙パック容器が提案されている（特許文献１参照）。
また、アルミニウム箔を含まない包装材料で基材の紙層の外側に、外側からデザイン層、白色印刷層、遮光色印刷層を設け、最内層に熱可塑性樹脂層を配した構成の紙パック容器の包装材が提案されている（特許文献２参照）。
さらに、包装材の表面にアルミペースト顔料、及びポリエチレンワックスを含有させたインキで遮光印刷層を設けた提案がある（特許文献３参照）。
これは、本発明の出願人の内の１人の提案に係るものであり、本発明はさらにこれを改良したものである。
その他、低沸点エステル系溶剤／又は低沸点アルコール系溶剤に分散したノンリーフィングタイプのアルミニウムペースト、ポリエチレンワックス及びシリカを含有するインキで遮光印刷層を設けたものが提案されている（特許文献４参照）。
これは、本発明の出願人の内の１人の提案に係るものであり、本発明はさらにこれを改良したものである。
For example, milk and juice are supplied to the market in a so-called roof-type paper pack container (gable top type) and are widely spread.
Since these containers have a structure in which an extremely thin synthetic resin layer is laminated on a thin paperboard, the rate of transmitting light is high.
The paper pack container is exposed to strong light for a long time by sunlight, indoor lighting in a store, and fluorescent lighting of a showcase during the distribution process. As a result, depending on the nature of the contents, there are not a few cases where it is affected by strong light and causes quality degradation or alteration.
In order to prevent the deterioration and deterioration of the contents due to the light transmission, a paper pack container provided with a light shielding layer has been proposed.
[Prior art documents]
[Patent Literature]
For example, a paper pack container is proposed in which a light-shielding printing layer made of an ink containing a carbon black pigment is provided between the base material of the packaging material and the innermost layer, and a colored printing layer located inside the light-shielding printing layer. (See Patent Document 1).
In addition, a paper pack container having a configuration in which a design layer, a white print layer, a light-shielding color print layer are provided from the outside and a thermoplastic resin layer is provided as the innermost layer on the outside of the paper layer of the base material with a packaging material not containing aluminum foil A packaging material has been proposed (see Patent Document 2).
Furthermore, there is a proposal in which a light-shielding printing layer is provided on the surface of the packaging material with an ink containing an aluminum paste pigment and polyethylene wax (see Patent Document 3).
This relates to the proposal of one of the applicants of the present invention, and the present invention further improves this.
In addition, a non-leafing type aluminum paste dispersed in a low-boiling ester solvent / or a low-boiling alcohol solvent, an ink containing polyethylene wax and silica provided with a light-shielding printing layer has been proposed (see Patent Document 4). ).
This relates to the proposal of one of the applicants of the present invention, and the present invention further improves this.
紙パック容器に対する光による内容物の飲料等の変質・劣化の防止には、遮光性のあるアルミニウム箔を紙容器の内側へ貼り付けることで、ほぼ完全に解決できる。然し乍ら、前記の構成のものは、遮光性において十分な効果が得られるものの、製造工程が増加し、結果コストが高くなる。また、これを焼却した場合、アルミの残渣が発生し、リサイクル上の難点があり、さらに検出感度の高い金属探知機を使用する場合には、反応感度を下げる必要等が生じ、検出作業に支障が生ずる場合もある。
また、カーボンブラックを含む黒色系インキによる遮光性印刷（特許文献１参照）は、遮光性に優れた効果を発揮するが、下地の黒色が影響してこの層の上に重ねて施す印刷の意匠性が悪くなる（くすみ等が出てデザイン印刷が綺麗に仕上がらない）欠点がある。
特許文献３及び４に開示されている銀インキは、アルミニウム顔料をインキ化したものであるが、包装材料及びこれを使用した包装容器、特に紙パック容器に印刷という極めて簡単な手段で優れた遮光性を与えて、その内容物の光による品質劣化を抑制できるうえ、内容物へ異臭を与えることがなく、その印刷層は密着性及び耐摩擦性に優れ、輸送時等のこすれにも耐えるため、遮光性が持続するといった優れた特徴を有する。
当該銀インキはグラビア印刷に適しており、包装材料に遮光性を付与するためにはこの銀インキをベタで印刷する必要がある。
通常、銀インキをベタでグラビア印刷する場合、その印刷速度は毎分１００~１５０ｍとされている。
特許文献３及び４に開示されている銀インキを用いて、毎分１５０ｍの印刷速度でグラビア印刷し、その上に同じ速度でデザイン印刷をグラビア印刷することは全く問題なく実施できたが、前記銀インキをベタ印刷した上に、デザイン印刷を同じ印刷速度でＵＶオフセット印刷すると密着性が不十分なため印刷時に印刷が剥がれたり、輸送時等における擦れによって印刷が剥がれたりする結果となった。
また、通常のＵＶオフセット印刷は毎分２５０~３００ｍの印刷速度であるため、連続運転により最高の生産性を達成するには、グラビア印刷による銀インキの印刷速度をＵＶオフセット印刷の最大印刷速度である毎分３００ｍにまで向上させる必要があった。
従って、本発明は、オフセット印刷並みの高速印刷が可能なグラビア印刷用銀インキであって、さらにその上に同じ速度でＵＶオフセット印刷可能なグラビア印刷用銀インキ及び当該銀インキを用いた包装容器を提供することを課題とする。 The prevention of alteration or deterioration of the beverage or the like of the contents of the paper pack container by light can be almost completely solved by sticking a light-shielding aluminum foil to the inside of the paper container. However, although the above-described structure can provide a sufficient light shielding effect, the number of manufacturing steps is increased, resulting in an increase in cost. Also, if this is incinerated, aluminum residues are generated and there are recycling difficulties. If a metal detector with high detection sensitivity is used, the reaction sensitivity needs to be lowered, which hinders detection work. May occur.
In addition, light-shielding printing with black ink containing carbon black (see Patent Document 1) exhibits an excellent effect on light-shielding properties, but the design of printing applied over this layer due to the influence of the black color of the base. There is a defect that the property becomes worse (the dullness etc. appears and the design printing does not finish cleanly).
The silver inks disclosed in Patent Documents 3 and 4 are obtained by converting an aluminum pigment into an ink. However, the light shielding is excellent by a very simple means of printing on a packaging material and a packaging container using the packaging material, particularly a paper pack container. In addition to preventing deterioration of the contents due to light of the contents, it does not give a strange odor to the contents, the printed layer has excellent adhesion and friction resistance, and resists rubbing during transportation. , And has excellent characteristics such as long-lasting light shielding properties.
The silver ink is suitable for gravure printing, and it is necessary to print the silver ink solidly in order to impart light shielding properties to the packaging material.
Usually, when performing solid gravure printing with silver ink, the printing speed is set to 100 to 150 m / min.
Using the silver ink disclosed in Patent Documents 3 and 4, gravure printing at a printing speed of 150 m / min and gravure printing on the same speed could be carried out without any problem. When solid printing was performed using silver ink and UV offset printing was performed at the same printing speed as the design printing, the adhesion was insufficient, resulting in peeling of the print during printing or peeling due to rubbing during transportation.
In addition, since normal UV offset printing has a printing speed of 250 to 300 m / min, in order to achieve the highest productivity by continuous operation, the silver ink printing speed by gravure printing should be the maximum printing speed of UV offset printing. It was necessary to improve to 300m / min.
Accordingly, the present invention is a gravure printing silver ink capable of high speed printing equivalent to offset printing, and further a gravure printing silver ink capable of UV offset printing at the same speed and a packaging container using the silver ink It is an issue to provide.
また、カーボンブラックを含む黒色系インキによる遮光性印刷（特許文献１参照）は、遮光性に優れた効果を発揮するが、下地の黒色が影響してこの層の上に重ねて施す印刷の意匠性が悪くなる（くすみ等が出てデザイン印刷が綺麗に仕上がらない）欠点がある。
特許文献３及び４に開示されている銀インキは、アルミニウム顔料をインキ化したものであるが、包装材料及びこれを使用した包装容器、特に紙パック容器に印刷という極めて簡単な手段で優れた遮光性を与えて、その内容物の光による品質劣化を抑制できるうえ、内容物へ異臭を与えることがなく、その印刷層は密着性及び耐摩擦性に優れ、輸送時等のこすれにも耐えるため、遮光性が持続するといった優れた特徴を有する。
当該銀インキはグラビア印刷に適しており、包装材料に遮光性を付与するためにはこの銀インキをベタで印刷する必要がある。
通常、銀インキをベタでグラビア印刷する場合、その印刷速度は毎分１００~１５０ｍとされている。
特許文献３及び４に開示されている銀インキを用いて、毎分１５０ｍの印刷速度でグラビア印刷し、その上に同じ速度でデザイン印刷をグラビア印刷することは全く問題なく実施できたが、前記銀インキをベタ印刷した上に、デザイン印刷を同じ印刷速度でＵＶオフセット印刷すると密着性が不十分なため印刷時に印刷が剥がれたり、輸送時等における擦れによって印刷が剥がれたりする結果となった。
また、通常のＵＶオフセット印刷は毎分２５０~３００ｍの印刷速度であるため、連続運転により最高の生産性を達成するには、グラビア印刷による銀インキの印刷速度をＵＶオフセット印刷の最大印刷速度である毎分３００ｍにまで向上させる必要があった。
従って、本発明は、オフセット印刷並みの高速印刷が可能なグラビア印刷用銀インキであって、さらにその上に同じ速度でＵＶオフセット印刷可能なグラビア印刷用銀インキ及び当該銀インキを用いた包装容器を提供することを課題とする。 The prevention of alteration or deterioration of the beverage or the like of the contents of the paper pack container by light can be almost completely solved by sticking a light-shielding aluminum foil to the inside of the paper container. However, although the above-described structure can provide a sufficient light shielding effect, the number of manufacturing steps is increased, resulting in an increase in cost. Also, if this is incinerated, aluminum residues are generated and there are recycling difficulties. If a metal detector with high detection sensitivity is used, the reaction sensitivity needs to be lowered, which hinders detection work. May occur.
In addition, light-shielding printing with black ink containing carbon black (see Patent Document 1) exhibits an excellent effect on light-shielding properties, but the design of printing applied over this layer due to the influence of the black color of the base. There is a defect that the property becomes worse (the dullness etc. appears and the design printing does not finish cleanly).
The silver inks disclosed in
The silver ink is suitable for gravure printing, and it is necessary to print the silver ink solidly in order to impart light shielding properties to the packaging material.
Usually, when performing solid gravure printing with silver ink, the printing speed is set to 100 to 150 m / min.
Using the silver ink disclosed in
In addition, since normal UV offset printing has a printing speed of 250 to 300 m / min, in order to achieve the highest productivity by continuous operation, the silver ink printing speed by gravure printing should be the maximum printing speed of UV offset printing. It was necessary to improve to 300m / min.
Accordingly, the present invention is a gravure printing silver ink capable of high speed printing equivalent to offset printing, and further a gravure printing silver ink capable of UV offset printing at the same speed and a packaging container using the silver ink It is an issue to provide.
上記の事情に鑑み、発明者らは、前記諸課題を解決するため鋭意研究の結果、銀インキの改良により前記課題を解決し、本発明を完成した。
即ち、下地印刷となるグラビア印刷用銀インキの密着性を高めること及び下地印刷の上に重ねるＵＶオフセット印刷との密着性が必要となる。
そこで、本発明者らは、特許文献４記載の銀インキにおいてバインダーとして使用されている硝化綿とポリエステル樹脂との組み合わせに替えて、ガラス転移点の異なる２種のポリエステル樹脂を組み合わせて用いることにより前記課題を解決した。
本発明の銀インキは、毎分３００ｍのグラビア印刷でも印刷濃度が不足したり、カスレが生じたりすることはなく、その上に同じ印刷速度でＵＶオフセット印刷（デザイン印刷）しても問題は生じなかった。
すなわち、グラビア印刷とＵＶオフセット印刷との印刷速度が同じなので、両者の連続印刷が可能となり、かつ、その印刷速度がほぼ２倍になったので、大幅な生産性向上が可能となった。
即ち、ポリエステル樹脂１００重量部に対して、アルミニウム顔料６０~１００重量部を含有している遮光性銀インキ組成物であって、前記ポリエステル樹脂がガラス転移点−２０~１０℃、数平均分子量５０００~２５０００及び水酸基価５~２０のポリエステル樹脂とガラス転移点３０~１００℃、数平均分子量５０００~２５０００及び水酸基価５~２０のポリエステル樹脂とを含み、その重量比率が１／１~１１／１である遮光性インキ組成物であり、前記遮光性銀インキ組成物に、ワックス２~１０重量部を添加した遮光性銀インキ組成物である。さらに、前記ワックスがポリエチレンワックスである遮光性銀インキ組成物であり、前記アルミニウム顔料が平均粒子径５~１５μｍのノンリーフィングタイプのアルミニウム顔料である遮光性銀インキ組成物でもある。また、前記遮光性銀インキ組成物に、更にポリイソシアネート１~１０重量部を添加した前記記載の遮光性銀インキ組成物であり、前記遮光性銀インキ組成物が、炭素数３~６のエステル系溶媒及び／又は炭素数３~６のケトン系溶媒を主成分とした溶媒中に溶解又は分散している遮光性銀インキ組成物である。さらに、板紙基材の上面及び下面のそれぞれに合成樹脂の層を備えた積層包装材料のその表側になる面に遮光性銀インキ組成物を用いて遮光性印刷層を設けると共に、前記遮光性印刷層の上にデザイン印刷層を設けた遮光性包装材であり前記記載の遮光性包装材から作成された包装容器である。 In view of the above circumstances, as a result of intensive studies to solve the above problems, the inventors have solved the above problems by improving silver ink and completed the present invention.
That is, it is necessary to improve the adhesion of the gravure printing silver ink to be the base printing and the adhesion to the UV offset printing to be superimposed on the base printing.
Therefore, the present inventors have used a combination of two types of polyester resins having different glass transition points instead of the combination of nitrified cotton and polyester resin used as a binder in the silver ink described inPatent Document 4. The said subject was solved.
The silver ink of the present invention does not have insufficient printing density or blur even in gravure printing at 300 m / min, and no problem occurs even when UV offset printing (design printing) is performed at the same printing speed. There wasn't.
That is, since the printing speeds of gravure printing and UV offset printing are the same, both of them can be continuously printed, and the printing speed is almost doubled, so that the productivity can be greatly improved.
That is, a light-shielding silver ink composition containing 60 to 100 parts by weight of an aluminum pigment with respect to 100 parts by weight of a polyester resin, wherein the polyester resin has a glass transition point of −20 to 10 ° C. and a number average molecular weight of 5000. A polyester resin having a glass transition point of 30 to 100 ° C., a number average molecular weight of 5000 to 25000 and a hydroxyl value of 5 to 20, and a weight ratio of 1/1 to 11/1. A light-shielding silver ink composition obtained by adding 2 to 10 parts by weight of wax to the light-shielding silver ink composition. Further, the light-shielding silver ink composition is a light-shielding silver ink composition in which the wax is polyethylene wax, and the aluminum pigment is a light-shielding silver ink composition in which the aluminum pigment is a non-leafing type aluminum pigment having an average particle diameter of 5 to 15 μm. The light-shielding silver ink composition as described above, wherein 1 to 10 parts by weight of polyisocyanate is further added to the light-shielding silver ink composition, wherein the light-shielding silver ink composition is an ester having 3 to 6 carbon atoms. It is a light-shielding silver ink composition dissolved or dispersed in a solvent mainly composed of a system solvent and / or a ketone system solvent having 3 to 6 carbon atoms. Furthermore, a light-shielding printing layer is provided on the surface of the laminated packaging material provided with a synthetic resin layer on each of the upper surface and the lower surface of the paperboard substrate using a light-shielding silver ink composition, and the light-shielding printing It is a light-shielding packaging material in which a design printing layer is provided on the layer, and is a packaging container made from the light-shielding packaging material described above.
即ち、下地印刷となるグラビア印刷用銀インキの密着性を高めること及び下地印刷の上に重ねるＵＶオフセット印刷との密着性が必要となる。
そこで、本発明者らは、特許文献４記載の銀インキにおいてバインダーとして使用されている硝化綿とポリエステル樹脂との組み合わせに替えて、ガラス転移点の異なる２種のポリエステル樹脂を組み合わせて用いることにより前記課題を解決した。
本発明の銀インキは、毎分３００ｍのグラビア印刷でも印刷濃度が不足したり、カスレが生じたりすることはなく、その上に同じ印刷速度でＵＶオフセット印刷（デザイン印刷）しても問題は生じなかった。
すなわち、グラビア印刷とＵＶオフセット印刷との印刷速度が同じなので、両者の連続印刷が可能となり、かつ、その印刷速度がほぼ２倍になったので、大幅な生産性向上が可能となった。
即ち、ポリエステル樹脂１００重量部に対して、アルミニウム顔料６０~１００重量部を含有している遮光性銀インキ組成物であって、前記ポリエステル樹脂がガラス転移点−２０~１０℃、数平均分子量５０００~２５０００及び水酸基価５~２０のポリエステル樹脂とガラス転移点３０~１００℃、数平均分子量５０００~２５０００及び水酸基価５~２０のポリエステル樹脂とを含み、その重量比率が１／１~１１／１である遮光性インキ組成物であり、前記遮光性銀インキ組成物に、ワックス２~１０重量部を添加した遮光性銀インキ組成物である。さらに、前記ワックスがポリエチレンワックスである遮光性銀インキ組成物であり、前記アルミニウム顔料が平均粒子径５~１５μｍのノンリーフィングタイプのアルミニウム顔料である遮光性銀インキ組成物でもある。また、前記遮光性銀インキ組成物に、更にポリイソシアネート１~１０重量部を添加した前記記載の遮光性銀インキ組成物であり、前記遮光性銀インキ組成物が、炭素数３~６のエステル系溶媒及び／又は炭素数３~６のケトン系溶媒を主成分とした溶媒中に溶解又は分散している遮光性銀インキ組成物である。さらに、板紙基材の上面及び下面のそれぞれに合成樹脂の層を備えた積層包装材料のその表側になる面に遮光性銀インキ組成物を用いて遮光性印刷層を設けると共に、前記遮光性印刷層の上にデザイン印刷層を設けた遮光性包装材であり前記記載の遮光性包装材から作成された包装容器である。 In view of the above circumstances, as a result of intensive studies to solve the above problems, the inventors have solved the above problems by improving silver ink and completed the present invention.
That is, it is necessary to improve the adhesion of the gravure printing silver ink to be the base printing and the adhesion to the UV offset printing to be superimposed on the base printing.
Therefore, the present inventors have used a combination of two types of polyester resins having different glass transition points instead of the combination of nitrified cotton and polyester resin used as a binder in the silver ink described in
The silver ink of the present invention does not have insufficient printing density or blur even in gravure printing at 300 m / min, and no problem occurs even when UV offset printing (design printing) is performed at the same printing speed. There wasn't.
That is, since the printing speeds of gravure printing and UV offset printing are the same, both of them can be continuously printed, and the printing speed is almost doubled, so that the productivity can be greatly improved.
That is, a light-shielding silver ink composition containing 60 to 100 parts by weight of an aluminum pigment with respect to 100 parts by weight of a polyester resin, wherein the polyester resin has a glass transition point of −20 to 10 ° C. and a number average molecular weight of 5000. A polyester resin having a glass transition point of 30 to 100 ° C., a number average molecular weight of 5000 to 25000 and a hydroxyl value of 5 to 20, and a weight ratio of 1/1 to 11/1. A light-shielding silver ink composition obtained by adding 2 to 10 parts by weight of wax to the light-shielding silver ink composition. Further, the light-shielding silver ink composition is a light-shielding silver ink composition in which the wax is polyethylene wax, and the aluminum pigment is a light-shielding silver ink composition in which the aluminum pigment is a non-leafing type aluminum pigment having an average particle diameter of 5 to 15 μm. The light-shielding silver ink composition as described above, wherein 1 to 10 parts by weight of polyisocyanate is further added to the light-shielding silver ink composition, wherein the light-shielding silver ink composition is an ester having 3 to 6 carbon atoms. It is a light-shielding silver ink composition dissolved or dispersed in a solvent mainly composed of a system solvent and / or a ketone system solvent having 3 to 6 carbon atoms. Furthermore, a light-shielding printing layer is provided on the surface of the laminated packaging material provided with a synthetic resin layer on each of the upper surface and the lower surface of the paperboard substrate using a light-shielding silver ink composition, and the light-shielding printing It is a light-shielding packaging material in which a design printing layer is provided on the layer, and is a packaging container made from the light-shielding packaging material described above.
本発明ではカーボンブラック等の黒色系の顔料を含まないから、輝度の高い銀色の遮光性印刷層を形成でき、この上にデザイン印刷をしても、下地がデザイン印刷に影響せず、通常の印刷で自由な色彩のデザイン印刷が可能である。
本発明の銀インキは、オフセット印刷で通常使用される印刷速度である毎分３００ｍでグラビア印刷ができるので、銀インキでグラビア印刷した後、同じラインで連続してＵＶオフセットによるデザイン印刷が可能となる。
即ち、本発明の銀インキを使用すれば、従来のグラビア印刷速度は毎分１５０ｍ程度であったが、毎分３００ｍでグラビア印刷とＵＶオフセット印刷とを連続して実施することが可能となり作業効率が著しく向上し、大幅なコスト低減の効果がある。
また、本発明の銀インキは、高速でグラビア印刷しても、インキの濃度低下がなく、かつ印刷のカスレが発生しない。さらに、銀インキ印刷層の上に重ねてデザイン印刷してもそのデザイン印刷が銀インキ印刷層と強く密着して剥がれることがない。もちろん臭気が少ないため包装容器の内容物の味や臭いを変化させることもない。
本発明のインキは、オフセットＵＶ（光硬化）インキへの密着性が著しく向上したので、次の重ね印刷までの養生時間を設ける必要がなくなり、例えば、オフセット印刷機の中に、グラビア印刷のユニットを収納する等ができ、印刷を一貫した流れ作業で行え、機器の設置面積を縮小でき、且つ作業性が著しく向上した。
光透過の阻止率は、従来のものと遜色のないものが得られる。 In the present invention, since a black pigment such as carbon black is not included, a high-brightness silver-colored light-shielding printing layer can be formed, and even if design printing is performed thereon, the base does not affect the design printing. It is possible to print design of any color by printing.
Since the silver ink of the present invention can perform gravure printing at a printing speed of 300 m / min, which is a printing speed normally used in offset printing, after gravure printing with silver ink, design printing by UV offset can be continuously performed on the same line. Become.
In other words, when the silver ink of the present invention is used, the conventional gravure printing speed is about 150 m / min. However, gravure printing and UV offset printing can be carried out continuously at 300 m / min. Is significantly improved, and there is a significant cost reduction effect.
In addition, the silver ink of the present invention does not cause a decrease in ink density even when gravure printing is performed at a high speed, and printing blur does not occur. Furthermore, even if design printing is performed on the silver ink printing layer, the design printing does not come into close contact with the silver ink printing layer and peel off. Of course, since there is little odor, the taste and smell of the contents of the packaging container are not changed.
The ink of the present invention has significantly improved adhesion to offset UV (photocuring) ink, so there is no need to provide a curing time until the next overprinting. For example, a gravure printing unit in an offset printing machine Etc., printing can be performed in a consistent flow operation, the installation area of the equipment can be reduced, and workability has been remarkably improved.
The light transmission blocking rate is comparable to the conventional one.
本発明の銀インキは、オフセット印刷で通常使用される印刷速度である毎分３００ｍでグラビア印刷ができるので、銀インキでグラビア印刷した後、同じラインで連続してＵＶオフセットによるデザイン印刷が可能となる。
即ち、本発明の銀インキを使用すれば、従来のグラビア印刷速度は毎分１５０ｍ程度であったが、毎分３００ｍでグラビア印刷とＵＶオフセット印刷とを連続して実施することが可能となり作業効率が著しく向上し、大幅なコスト低減の効果がある。
また、本発明の銀インキは、高速でグラビア印刷しても、インキの濃度低下がなく、かつ印刷のカスレが発生しない。さらに、銀インキ印刷層の上に重ねてデザイン印刷してもそのデザイン印刷が銀インキ印刷層と強く密着して剥がれることがない。もちろん臭気が少ないため包装容器の内容物の味や臭いを変化させることもない。
本発明のインキは、オフセットＵＶ（光硬化）インキへの密着性が著しく向上したので、次の重ね印刷までの養生時間を設ける必要がなくなり、例えば、オフセット印刷機の中に、グラビア印刷のユニットを収納する等ができ、印刷を一貫した流れ作業で行え、機器の設置面積を縮小でき、且つ作業性が著しく向上した。
光透過の阻止率は、従来のものと遜色のないものが得られる。 In the present invention, since a black pigment such as carbon black is not included, a high-brightness silver-colored light-shielding printing layer can be formed, and even if design printing is performed thereon, the base does not affect the design printing. It is possible to print design of any color by printing.
Since the silver ink of the present invention can perform gravure printing at a printing speed of 300 m / min, which is a printing speed normally used in offset printing, after gravure printing with silver ink, design printing by UV offset can be continuously performed on the same line. Become.
In other words, when the silver ink of the present invention is used, the conventional gravure printing speed is about 150 m / min. However, gravure printing and UV offset printing can be carried out continuously at 300 m / min. Is significantly improved, and there is a significant cost reduction effect.
In addition, the silver ink of the present invention does not cause a decrease in ink density even when gravure printing is performed at a high speed, and printing blur does not occur. Furthermore, even if design printing is performed on the silver ink printing layer, the design printing does not come into close contact with the silver ink printing layer and peel off. Of course, since there is little odor, the taste and smell of the contents of the packaging container are not changed.
The ink of the present invention has significantly improved adhesion to offset UV (photocuring) ink, so there is no need to provide a curing time until the next overprinting. For example, a gravure printing unit in an offset printing machine Etc., printing can be performed in a consistent flow operation, the installation area of the equipment can be reduced, and workability has been remarkably improved.
The light transmission blocking rate is comparable to the conventional one.
各図面は、サンプルの光透過率を比較測定したものである。
図１は、比較試験例に記載の包装材基材に実施例３記載の銀インキで、ベタ印刷をして、遮光性印刷層を設けたものである。
図２は、比較試験例に記載の包装材基材に、東京インキ（株）製ＬＲＣ−ＮＴ９１０墨で黒色印刷したものである。 Each drawing is a comparative measurement of the light transmittance of the sample.
FIG. 1 shows a case in which a light-shielding printing layer is provided by solid printing with the silver ink described in Example 3 on a packaging material substrate described in a comparative test example.
FIG. 2 shows a black base printed on a packaging material base material described in the comparative test example with LRC-NT910 ink manufactured by Tokyo Ink Co., Ltd.
図１は、比較試験例に記載の包装材基材に実施例３記載の銀インキで、ベタ印刷をして、遮光性印刷層を設けたものである。
図２は、比較試験例に記載の包装材基材に、東京インキ（株）製ＬＲＣ−ＮＴ９１０墨で黒色印刷したものである。 Each drawing is a comparative measurement of the light transmittance of the sample.
FIG. 1 shows a case in which a light-shielding printing layer is provided by solid printing with the silver ink described in Example 3 on a packaging material substrate described in a comparative test example.
FIG. 2 shows a black base printed on a packaging material base material described in the comparative test example with LRC-NT910 ink manufactured by Tokyo Ink Co., Ltd.
本発明は、本発明の銀インキを用いて、紙パック容器等への印刷に際し、先ず、グラビア印刷で遮光性を付与する印刷を行い、次いでその上に重ねて、ＵＶオフセット印刷でデザイン印刷を行うことで、その目的を達成できるものである。
即ち、本発明の包装容器は、本発明の銀インキを板紙基材の内面及び外面に合成樹脂層を備えた積層包装材料（包装材基材）の遮光性を必要とする部分にベタ印刷し（遮光性付与印刷層）、その上に更にデザイン印刷層を設け、これを紙パック容器に成形組み立てたものである。
本発明の銀インキにおいては、バインダーとして２種類のポリエステル樹脂を用いる。１つはガラス転移点（Ｔｇ）が−２０~１０℃、数平均分子量５０００~２５０００及び水酸基価５~２０のポリエステル樹脂で、もう一つはガラス転移点（Ｔｇ）が３０~１００℃、数平均分子量５０００~２５０００及び水酸基価５~２０のポリエステル樹脂である。
これらガラス転移点の低いポリエステル樹脂とガラス転移点が高いポリエステル樹脂とを組み合わせることにより、毎分３００ｍの高速印刷においても印刷濃度が低下することがなく、包装材基材との密着性に優れ、さらにその上にＵＶオフセット印刷によるデザイン印刷した場合、そのデザイン印刷との密着性に優れているため輸送時などにおいて擦れて剥がれることがない。更に、印刷物を重ねたときに印刷面とその上に重なる基材の未印刷面とが付着することがない。即ち、耐ブロッキング性にも優れる。
これら２種のポリエステル樹脂の配合割合は、重量部で１／１~１１／１（ガラス転移点の低いポリエステル樹脂／ガラス転移点の高いポリエステル樹脂）である。この混合比率が１１／１を超えると、ブロッキングするため実質的に使用できず、この比率が１／１未満では包装材基材及びＵＶオフセット印刷との密着性が不十分となる。
なお、１種類のポリエステル樹脂だけで密着性と耐ブロッキング性とを両立させることはできなかった。例えば、ガラス転移点３０~５０のポリエステル樹脂から１種類を選んで用いた場合、特に密着性が不十分で本発明の効果を実現できなかった。
本発明の銀インキに用いるアルミニウム顔料は、平均粒径５~１５μｍのノンリーフィングタイプのアルミニウムで、酢酸ｎ−プロピル中に分散したものである。
アルミニウム顔料の平均粒径が５μｍに満たないものは、輝度が大きく低下するため意匠性に欠けたものとなるばかりでなく、インキ皮膜の密着性が低下するため剥がれやすくなる。
また、１５μｍを超えるものは、インキ中で沈降が起こりやすく、印刷したとき抜けが多くなって隠蔽性が低下するため遮光性が低下する。なお、ここでの平均粒径はレーザ法（ＭＩＣＲＯＴＲＡＣ ９３２０×１００ Ｈｏｎｅｙｗｅｌｌ製）による測定値である。
リーフィングタイプのアルミニウム顔料は、高輝度が実現しやすく隠蔽性にも優れているが、印刷したとき表面に浮かび上がるため、耐摩擦性及びインキ皮膜の密着性が悪い。一方、ノンリーフィングタイプは、インキ皮膜中にランダムに分散する性質があるため薄片のアルミニウム顔料間にインキ材料に用いる樹脂が入り込みやすくなる。その結果、インキ皮膜の密着性が向上し剥がれ落ちることがなく耐磨耗性も改善される。
前記アルミニウム顔料の添加量は、前記ポリエステル樹脂１００重量部に対し６０~１００重量部である。
アルミニウム顔料の添加量が６０重量部未満では、輝度が低下するため印刷物が意匠性に欠けたものとなり、印刷物の遮光性も不十分となるため好ましくない。また、１００重量部を超えると版詰まり、ツーツー汚れ等が起きやすく、密着性も低下するため好ましくない。
本発明の銀インキでは、耐摩擦性向上のためにワックスを添加するのが好ましい。用いるワックスとしてポリエチレンワックス、ポリプロピレンワックス、ポリ（エチレン−プロピレン）共重合体ワックス、カルバナワックス、パラフィンワックス、マイクロクリスタリンワックス、キャンデリラワックス、白ロウ等が挙げられるが、重量平均分子量１０００~５０００のポリエチレンワックスが特に好ましく用いられ、その添加量は、前記ポリエステル樹脂１００重量部に対し２~１０重量部である。
また、銀インキによる遮光性印刷及びデザイン印刷の上に、オーバーコートすることによっても耐摩擦性が改善されるので、特に、銀インキにワックスを添加しない場合は、印刷面の上にオーバーコート層設けるのが好ましい。
このオーバーコート層は、ポリエチレン系樹脂、ポリプロピレン系樹脂、エチレン−ビニルアセテート系樹脂、エチレン−エチルアクリレート系樹脂、アセテートニトロセルロース系樹脂、ニトロセルロース系樹脂、ポリアミド系樹脂、アクリル系樹脂、ポリウレタン系樹脂、ポリエステル系樹脂、エポキシ系樹脂、シリコン系樹脂、ふっ素系樹脂等を主成分とする樹脂やこれらの樹脂に充填剤、滑剤、紫外線吸収剤、酸化防止剤、撥水剤、撥油剤等の助剤を加えた樹脂組成物を印刷面に塗布することによって形成できる。
本発明の銀インキに、さらにポリイソシアネートを配合すると密着性が向上するため、高速印刷により適したものとなる。この効果は、ポリイソシアネートとポリエステル樹脂の水酸基とが反応してウレタン結合をつくることによるものと推察される。
このポリイソシアネートの添加量は、前記ポリエステル樹脂１００重量部に対し１~１０重量部が好ましく、その種類は特に限定されるものではないが、無黄変タイプのポリイソシアネートが好適に用いられる。
以上、本発明の銀インキを、溶媒を除いた組成物として説明してきたが、本発明の銀インキに用いる原材料は全て有機溶媒に溶解或は分散しているものを用いている。
すなわち、２種のポリエステル樹脂は酢酸エチルとメチルエチルケトンとの混合溶媒に３０重量％程度溶解しているもの、ポリエチレンワックスはイソプロピルアルコール中に２５重量％程度分散しているもの、アルミニウム顔料は酢酸ｎ−プロピルに７０重量％程度分散したペースト状のもの、ポリイソシアネートは酢酸エチルに７５重量％程度溶解しているものである。
これらの溶媒は、原料の入手先や溶解性に従って適宜選択され、その濃度も適宜決められるものであるが、残留溶媒による臭気の問題を避けるためエステル系溶媒及び／又はケトン系溶媒で、特に何れも炭素数で３~６の低級のものが好ましく用いられる。低級のアルコール系の溶媒も少量であれば使用可能であるが、本発明で用いるポリエステル樹脂が低級のアルコール系溶媒への溶解性が小さいため、多量に用いることはできない。
なお、本発明の銀インキでは、その品質の保全・安定性を維持したり、印刷に適した粘度に調整したりするために濃度調整用の有機溶媒が用いられるが、これらの有機溶媒も上記と同様にエステル系溶媒及び／又はケトン系溶媒で、特に何れも炭素数で３~６の低級のものが好ましく用いられる。
本発明の銀インキは、上記で説明した原材料、すなわち、２種類のポリエステル樹脂とアルミニウム顔料と、更に場合によっては、ワックスとポリイソシアネートとを混合し、その混合物に濃度調節用の溶媒を加えて製造される。
さらに、本発明の銀インキには、必要に応じて印刷用インキに用いられる公知の助剤を使用してもよい。例えば、可塑剤、レベリング剤、界面活性剤、分散剤、消泡剤などを用いてもよい、
前記の構成により、本発明の銀インキは、包装材基材及びＵＶオフセットインキとの密着性が向上し、銀インキの印刷とそれに連続して行われるオフセット印刷とを通常のオフセット印刷で用いられる速度である毎分３００ｍで行ってもこれに耐えられる銀インキが得られた。
なお、本発明の銀インキは、グラビア印刷に適し、且つ高速印刷適正を有する。
本発明の銀インキによる遮光印刷層の厚さは、１~１０μｍが好ましい。１μｍ未満では、遮光性の付与効果が不十分であり、１０μｍを超えると実用上過剰量となるばかりでなく、コストアップとなる。
さらに、本発明の銀インキで印刷した表面にＵＶオフセット印刷ができ、その印刷方法は、ＵＶオフセット印刷の常法による。その使用にあたって、格別の設備は必要としない。 In the present invention, when printing on a paper pack container or the like using the silver ink of the present invention, first, printing that imparts light-shielding properties by gravure printing is performed, and then superimposed on it, design printing is performed by UV offset printing. By doing it, you can achieve that goal.
That is, the packaging container of the present invention is obtained by solid-printing the silver ink of the present invention on a portion of a laminated packaging material (packaging material substrate) having a synthetic resin layer on the inner surface and outer surface of the paperboard substrate that requires light shielding. (Light-shielding imparted print layer), a design print layer is further provided thereon, and this is molded and assembled into a paper pack container.
In the silver ink of the present invention, two types of polyester resins are used as binders. One is a polyester resin having a glass transition point (Tg) of −20 to 10 ° C., a number average molecular weight of 5000 to 25000 and a hydroxyl value of 5 to 20, and the other is a glass transition point (Tg) of 30 to 100 ° C. A polyester resin having an average molecular weight of 5000 to 25000 and a hydroxyl value of 5 to 20.
By combining these polyester resins having a low glass transition point and polyester resins having a high glass transition point, the printing density does not decrease even in high-speed printing at 300 m / min, and the adhesiveness to the packaging material substrate is excellent. Furthermore, when design printing by UV offset printing is performed thereon, since it has excellent adhesion with the design printing, it is not rubbed and peeled off during transportation. Further, when the printed materials are stacked, the printed surface and the unprinted surface of the base material overlapping therewith are not attached. That is, it is excellent in blocking resistance.
The blending ratio of these two kinds of polyester resins is 1/1 to 11/1 by weight (polyester resin having a low glass transition point / polyester resin having a high glass transition point). If this mixing ratio exceeds 11/1, it cannot be used substantially because of blocking, and if this ratio is less than 1/1, the adhesion to the packaging material substrate and UV offset printing becomes insufficient.
In addition, adhesiveness and blocking resistance could not be made compatible with only one type of polyester resin. For example, when one kind of polyester resin having a glass transition point of 30 to 50 is selected and used, the effect of the present invention cannot be realized due to insufficient adhesion.
The aluminum pigment used in the silver ink of the present invention is non-leafing type aluminum having an average particle diameter of 5 to 15 μm and is dispersed in n-propyl acetate.
When the average particle size of the aluminum pigment is less than 5 μm, not only the brightness is greatly reduced and the design property is lacking, but also the adhesion of the ink film is lowered, and the aluminum pigment is easily peeled off.
In addition, when the thickness exceeds 15 μm, sedimentation tends to occur in the ink, and when printing is performed, there are many omissions and the concealing property is lowered, so that the light shielding property is lowered. In addition, the average particle diameter here is a measured value by a laser method (manufactured by MICROTRAC 9320 × 100 Honeywell).
Leafing type aluminum pigments are easy to achieve high brightness and excellent in concealment properties, but they float on the surface when printed, and therefore have poor friction resistance and ink film adhesion. On the other hand, since the non-leafing type has the property of being randomly dispersed in the ink film, the resin used for the ink material is likely to enter between the thin aluminum pigments. As a result, the adhesion of the ink film is improved and the abrasion resistance is improved without peeling off.
The addition amount of the aluminum pigment is 60 to 100 parts by weight with respect to 100 parts by weight of the polyester resin.
If the amount of the aluminum pigment added is less than 60 parts by weight, the brightness is lowered, so that the printed material lacks design properties, and the light shielding property of the printed material becomes insufficient. On the other hand, when the amount exceeds 100 parts by weight, it is not preferable because plate clogging, two-to-stain, etc. are likely to occur and the adhesiveness is lowered.
In the silver ink of the present invention, it is preferable to add a wax in order to improve the friction resistance. Examples of the wax to be used include polyethylene wax, polypropylene wax, poly (ethylene-propylene) copolymer wax, carbana wax, paraffin wax, microcrystalline wax, candelilla wax, white wax and the like, but having a weight average molecular weight of 1,000 to 5,000. Polyethylene wax is particularly preferably used, and the amount added is 2 to 10 parts by weight with respect to 100 parts by weight of the polyester resin.
In addition, the overcoat layer on the printed surface, especially when no wax is added to the silver ink, improves the abrasion resistance by overcoating on the light-shielding printing and design printing with silver ink. It is preferable to provide it.
This overcoat layer is made of polyethylene resin, polypropylene resin, ethylene-vinyl acetate resin, ethylene-ethyl acrylate resin, acetate nitrocellulose resin, nitrocellulose resin, polyamide resin, acrylic resin, polyurethane resin. , Polyester resins, epoxy resins, silicon resins, fluorine resins, etc., and those resins with fillers, lubricants, UV absorbers, antioxidants, water repellents, oil repellents, etc. It can form by apply | coating the resin composition which added the agent to the printing surface.
When the polyisocyanate is further added to the silver ink of the present invention, the adhesion is improved, so that it is more suitable for high-speed printing. This effect is presumed to be due to the reaction between the polyisocyanate and the hydroxyl group of the polyester resin to form a urethane bond.
The addition amount of the polyisocyanate is preferably 1 to 10 parts by weight with respect to 100 parts by weight of the polyester resin, and the type thereof is not particularly limited, but a non-yellowing type polyisocyanate is preferably used.
As mentioned above, although the silver ink of this invention was demonstrated as a composition except a solvent, all the raw materials used for the silver ink of this invention have used what was melt | dissolved or disperse | distributed to the organic solvent.
That is, two types of polyester resins are those in which about 30% by weight is dissolved in a mixed solvent of ethyl acetate and methyl ethyl ketone, polyethylene wax is about 25% by weight dispersed in isopropyl alcohol, and aluminum pigment is n-acetate. A paste in which about 70% by weight is dispersed in propyl, and polyisocyanate is dissolved in about 75% by weight in ethyl acetate.
These solvents are appropriately selected according to the source and solubility of the raw materials, and the concentration thereof is also determined as appropriate. In order to avoid the problem of odor due to the residual solvent, ester solvents and / or ketone solvents are used. Also, those having a lower carbon number of 3 to 6 are preferably used. A small amount of a low-alcohol solvent can be used, but the polyester resin used in the present invention cannot be used in a large amount because of its low solubility in a low-alcohol solvent.
In addition, in the silver ink of the present invention, an organic solvent for concentration adjustment is used in order to maintain its quality maintenance and stability, or to adjust the viscosity to be suitable for printing. In the same manner as above, ester solvents and / or ketone solvents, particularly those having a lower carbon number of 3 to 6 are preferably used.
The silver ink of the present invention is prepared by mixing the raw materials described above, that is, two types of polyester resin and an aluminum pigment, and, in some cases, a wax and a polyisocyanate, and adding a concentration adjusting solvent to the mixture. Manufactured.
Furthermore, you may use the well-known adjuvant used for the printing ink as needed for the silver ink of this invention. For example, a plasticizer, a leveling agent, a surfactant, a dispersant, an antifoaming agent, etc. may be used.
With the above configuration, the silver ink of the present invention has improved adhesion to the packaging material base material and the UV offset ink, and the silver ink printing and the offset printing performed successively are used in normal offset printing. A silver ink that can withstand this even at a speed of 300 m / min was obtained.
The silver ink of the present invention is suitable for gravure printing and has high-speed printing suitability.
The thickness of the light-shielding printing layer using the silver ink of the present invention is preferably 1 to 10 μm. If the thickness is less than 1 μm, the light-shielding effect is insufficient, and if it exceeds 10 μm, not only is it practically excessive, but the cost is increased.
Furthermore, UV offset printing can be performed on the surface printed with the silver ink of the present invention, and the printing method is based on the usual method of UV offset printing. No special equipment is required for its use.
即ち、本発明の包装容器は、本発明の銀インキを板紙基材の内面及び外面に合成樹脂層を備えた積層包装材料（包装材基材）の遮光性を必要とする部分にベタ印刷し（遮光性付与印刷層）、その上に更にデザイン印刷層を設け、これを紙パック容器に成形組み立てたものである。
本発明の銀インキにおいては、バインダーとして２種類のポリエステル樹脂を用いる。１つはガラス転移点（Ｔｇ）が−２０~１０℃、数平均分子量５０００~２５０００及び水酸基価５~２０のポリエステル樹脂で、もう一つはガラス転移点（Ｔｇ）が３０~１００℃、数平均分子量５０００~２５０００及び水酸基価５~２０のポリエステル樹脂である。
これらガラス転移点の低いポリエステル樹脂とガラス転移点が高いポリエステル樹脂とを組み合わせることにより、毎分３００ｍの高速印刷においても印刷濃度が低下することがなく、包装材基材との密着性に優れ、さらにその上にＵＶオフセット印刷によるデザイン印刷した場合、そのデザイン印刷との密着性に優れているため輸送時などにおいて擦れて剥がれることがない。更に、印刷物を重ねたときに印刷面とその上に重なる基材の未印刷面とが付着することがない。即ち、耐ブロッキング性にも優れる。
これら２種のポリエステル樹脂の配合割合は、重量部で１／１~１１／１（ガラス転移点の低いポリエステル樹脂／ガラス転移点の高いポリエステル樹脂）である。この混合比率が１１／１を超えると、ブロッキングするため実質的に使用できず、この比率が１／１未満では包装材基材及びＵＶオフセット印刷との密着性が不十分となる。
なお、１種類のポリエステル樹脂だけで密着性と耐ブロッキング性とを両立させることはできなかった。例えば、ガラス転移点３０~５０のポリエステル樹脂から１種類を選んで用いた場合、特に密着性が不十分で本発明の効果を実現できなかった。
本発明の銀インキに用いるアルミニウム顔料は、平均粒径５~１５μｍのノンリーフィングタイプのアルミニウムで、酢酸ｎ−プロピル中に分散したものである。
アルミニウム顔料の平均粒径が５μｍに満たないものは、輝度が大きく低下するため意匠性に欠けたものとなるばかりでなく、インキ皮膜の密着性が低下するため剥がれやすくなる。
また、１５μｍを超えるものは、インキ中で沈降が起こりやすく、印刷したとき抜けが多くなって隠蔽性が低下するため遮光性が低下する。なお、ここでの平均粒径はレーザ法（ＭＩＣＲＯＴＲＡＣ ９３２０×１００ Ｈｏｎｅｙｗｅｌｌ製）による測定値である。
リーフィングタイプのアルミニウム顔料は、高輝度が実現しやすく隠蔽性にも優れているが、印刷したとき表面に浮かび上がるため、耐摩擦性及びインキ皮膜の密着性が悪い。一方、ノンリーフィングタイプは、インキ皮膜中にランダムに分散する性質があるため薄片のアルミニウム顔料間にインキ材料に用いる樹脂が入り込みやすくなる。その結果、インキ皮膜の密着性が向上し剥がれ落ちることがなく耐磨耗性も改善される。
前記アルミニウム顔料の添加量は、前記ポリエステル樹脂１００重量部に対し６０~１００重量部である。
アルミニウム顔料の添加量が６０重量部未満では、輝度が低下するため印刷物が意匠性に欠けたものとなり、印刷物の遮光性も不十分となるため好ましくない。また、１００重量部を超えると版詰まり、ツーツー汚れ等が起きやすく、密着性も低下するため好ましくない。
本発明の銀インキでは、耐摩擦性向上のためにワックスを添加するのが好ましい。用いるワックスとしてポリエチレンワックス、ポリプロピレンワックス、ポリ（エチレン−プロピレン）共重合体ワックス、カルバナワックス、パラフィンワックス、マイクロクリスタリンワックス、キャンデリラワックス、白ロウ等が挙げられるが、重量平均分子量１０００~５０００のポリエチレンワックスが特に好ましく用いられ、その添加量は、前記ポリエステル樹脂１００重量部に対し２~１０重量部である。
また、銀インキによる遮光性印刷及びデザイン印刷の上に、オーバーコートすることによっても耐摩擦性が改善されるので、特に、銀インキにワックスを添加しない場合は、印刷面の上にオーバーコート層設けるのが好ましい。
このオーバーコート層は、ポリエチレン系樹脂、ポリプロピレン系樹脂、エチレン−ビニルアセテート系樹脂、エチレン−エチルアクリレート系樹脂、アセテートニトロセルロース系樹脂、ニトロセルロース系樹脂、ポリアミド系樹脂、アクリル系樹脂、ポリウレタン系樹脂、ポリエステル系樹脂、エポキシ系樹脂、シリコン系樹脂、ふっ素系樹脂等を主成分とする樹脂やこれらの樹脂に充填剤、滑剤、紫外線吸収剤、酸化防止剤、撥水剤、撥油剤等の助剤を加えた樹脂組成物を印刷面に塗布することによって形成できる。
本発明の銀インキに、さらにポリイソシアネートを配合すると密着性が向上するため、高速印刷により適したものとなる。この効果は、ポリイソシアネートとポリエステル樹脂の水酸基とが反応してウレタン結合をつくることによるものと推察される。
このポリイソシアネートの添加量は、前記ポリエステル樹脂１００重量部に対し１~１０重量部が好ましく、その種類は特に限定されるものではないが、無黄変タイプのポリイソシアネートが好適に用いられる。
以上、本発明の銀インキを、溶媒を除いた組成物として説明してきたが、本発明の銀インキに用いる原材料は全て有機溶媒に溶解或は分散しているものを用いている。
すなわち、２種のポリエステル樹脂は酢酸エチルとメチルエチルケトンとの混合溶媒に３０重量％程度溶解しているもの、ポリエチレンワックスはイソプロピルアルコール中に２５重量％程度分散しているもの、アルミニウム顔料は酢酸ｎ−プロピルに７０重量％程度分散したペースト状のもの、ポリイソシアネートは酢酸エチルに７５重量％程度溶解しているものである。
これらの溶媒は、原料の入手先や溶解性に従って適宜選択され、その濃度も適宜決められるものであるが、残留溶媒による臭気の問題を避けるためエステル系溶媒及び／又はケトン系溶媒で、特に何れも炭素数で３~６の低級のものが好ましく用いられる。低級のアルコール系の溶媒も少量であれば使用可能であるが、本発明で用いるポリエステル樹脂が低級のアルコール系溶媒への溶解性が小さいため、多量に用いることはできない。
なお、本発明の銀インキでは、その品質の保全・安定性を維持したり、印刷に適した粘度に調整したりするために濃度調整用の有機溶媒が用いられるが、これらの有機溶媒も上記と同様にエステル系溶媒及び／又はケトン系溶媒で、特に何れも炭素数で３~６の低級のものが好ましく用いられる。
本発明の銀インキは、上記で説明した原材料、すなわち、２種類のポリエステル樹脂とアルミニウム顔料と、更に場合によっては、ワックスとポリイソシアネートとを混合し、その混合物に濃度調節用の溶媒を加えて製造される。
さらに、本発明の銀インキには、必要に応じて印刷用インキに用いられる公知の助剤を使用してもよい。例えば、可塑剤、レベリング剤、界面活性剤、分散剤、消泡剤などを用いてもよい、
前記の構成により、本発明の銀インキは、包装材基材及びＵＶオフセットインキとの密着性が向上し、銀インキの印刷とそれに連続して行われるオフセット印刷とを通常のオフセット印刷で用いられる速度である毎分３００ｍで行ってもこれに耐えられる銀インキが得られた。
なお、本発明の銀インキは、グラビア印刷に適し、且つ高速印刷適正を有する。
本発明の銀インキによる遮光印刷層の厚さは、１~１０μｍが好ましい。１μｍ未満では、遮光性の付与効果が不十分であり、１０μｍを超えると実用上過剰量となるばかりでなく、コストアップとなる。
さらに、本発明の銀インキで印刷した表面にＵＶオフセット印刷ができ、その印刷方法は、ＵＶオフセット印刷の常法による。その使用にあたって、格別の設備は必要としない。 In the present invention, when printing on a paper pack container or the like using the silver ink of the present invention, first, printing that imparts light-shielding properties by gravure printing is performed, and then superimposed on it, design printing is performed by UV offset printing. By doing it, you can achieve that goal.
That is, the packaging container of the present invention is obtained by solid-printing the silver ink of the present invention on a portion of a laminated packaging material (packaging material substrate) having a synthetic resin layer on the inner surface and outer surface of the paperboard substrate that requires light shielding. (Light-shielding imparted print layer), a design print layer is further provided thereon, and this is molded and assembled into a paper pack container.
In the silver ink of the present invention, two types of polyester resins are used as binders. One is a polyester resin having a glass transition point (Tg) of −20 to 10 ° C., a number average molecular weight of 5000 to 25000 and a hydroxyl value of 5 to 20, and the other is a glass transition point (Tg) of 30 to 100 ° C. A polyester resin having an average molecular weight of 5000 to 25000 and a hydroxyl value of 5 to 20.
By combining these polyester resins having a low glass transition point and polyester resins having a high glass transition point, the printing density does not decrease even in high-speed printing at 300 m / min, and the adhesiveness to the packaging material substrate is excellent. Furthermore, when design printing by UV offset printing is performed thereon, since it has excellent adhesion with the design printing, it is not rubbed and peeled off during transportation. Further, when the printed materials are stacked, the printed surface and the unprinted surface of the base material overlapping therewith are not attached. That is, it is excellent in blocking resistance.
The blending ratio of these two kinds of polyester resins is 1/1 to 11/1 by weight (polyester resin having a low glass transition point / polyester resin having a high glass transition point). If this mixing ratio exceeds 11/1, it cannot be used substantially because of blocking, and if this ratio is less than 1/1, the adhesion to the packaging material substrate and UV offset printing becomes insufficient.
In addition, adhesiveness and blocking resistance could not be made compatible with only one type of polyester resin. For example, when one kind of polyester resin having a glass transition point of 30 to 50 is selected and used, the effect of the present invention cannot be realized due to insufficient adhesion.
The aluminum pigment used in the silver ink of the present invention is non-leafing type aluminum having an average particle diameter of 5 to 15 μm and is dispersed in n-propyl acetate.
When the average particle size of the aluminum pigment is less than 5 μm, not only the brightness is greatly reduced and the design property is lacking, but also the adhesion of the ink film is lowered, and the aluminum pigment is easily peeled off.
In addition, when the thickness exceeds 15 μm, sedimentation tends to occur in the ink, and when printing is performed, there are many omissions and the concealing property is lowered, so that the light shielding property is lowered. In addition, the average particle diameter here is a measured value by a laser method (manufactured by MICROTRAC 9320 × 100 Honeywell).
Leafing type aluminum pigments are easy to achieve high brightness and excellent in concealment properties, but they float on the surface when printed, and therefore have poor friction resistance and ink film adhesion. On the other hand, since the non-leafing type has the property of being randomly dispersed in the ink film, the resin used for the ink material is likely to enter between the thin aluminum pigments. As a result, the adhesion of the ink film is improved and the abrasion resistance is improved without peeling off.
The addition amount of the aluminum pigment is 60 to 100 parts by weight with respect to 100 parts by weight of the polyester resin.
If the amount of the aluminum pigment added is less than 60 parts by weight, the brightness is lowered, so that the printed material lacks design properties, and the light shielding property of the printed material becomes insufficient. On the other hand, when the amount exceeds 100 parts by weight, it is not preferable because plate clogging, two-to-stain, etc. are likely to occur and the adhesiveness is lowered.
In the silver ink of the present invention, it is preferable to add a wax in order to improve the friction resistance. Examples of the wax to be used include polyethylene wax, polypropylene wax, poly (ethylene-propylene) copolymer wax, carbana wax, paraffin wax, microcrystalline wax, candelilla wax, white wax and the like, but having a weight average molecular weight of 1,000 to 5,000. Polyethylene wax is particularly preferably used, and the amount added is 2 to 10 parts by weight with respect to 100 parts by weight of the polyester resin.
In addition, the overcoat layer on the printed surface, especially when no wax is added to the silver ink, improves the abrasion resistance by overcoating on the light-shielding printing and design printing with silver ink. It is preferable to provide it.
This overcoat layer is made of polyethylene resin, polypropylene resin, ethylene-vinyl acetate resin, ethylene-ethyl acrylate resin, acetate nitrocellulose resin, nitrocellulose resin, polyamide resin, acrylic resin, polyurethane resin. , Polyester resins, epoxy resins, silicon resins, fluorine resins, etc., and those resins with fillers, lubricants, UV absorbers, antioxidants, water repellents, oil repellents, etc. It can form by apply | coating the resin composition which added the agent to the printing surface.
When the polyisocyanate is further added to the silver ink of the present invention, the adhesion is improved, so that it is more suitable for high-speed printing. This effect is presumed to be due to the reaction between the polyisocyanate and the hydroxyl group of the polyester resin to form a urethane bond.
The addition amount of the polyisocyanate is preferably 1 to 10 parts by weight with respect to 100 parts by weight of the polyester resin, and the type thereof is not particularly limited, but a non-yellowing type polyisocyanate is preferably used.
As mentioned above, although the silver ink of this invention was demonstrated as a composition except a solvent, all the raw materials used for the silver ink of this invention have used what was melt | dissolved or disperse | distributed to the organic solvent.
That is, two types of polyester resins are those in which about 30% by weight is dissolved in a mixed solvent of ethyl acetate and methyl ethyl ketone, polyethylene wax is about 25% by weight dispersed in isopropyl alcohol, and aluminum pigment is n-acetate. A paste in which about 70% by weight is dispersed in propyl, and polyisocyanate is dissolved in about 75% by weight in ethyl acetate.
These solvents are appropriately selected according to the source and solubility of the raw materials, and the concentration thereof is also determined as appropriate. In order to avoid the problem of odor due to the residual solvent, ester solvents and / or ketone solvents are used. Also, those having a lower carbon number of 3 to 6 are preferably used. A small amount of a low-alcohol solvent can be used, but the polyester resin used in the present invention cannot be used in a large amount because of its low solubility in a low-alcohol solvent.
In addition, in the silver ink of the present invention, an organic solvent for concentration adjustment is used in order to maintain its quality maintenance and stability, or to adjust the viscosity to be suitable for printing. In the same manner as above, ester solvents and / or ketone solvents, particularly those having a lower carbon number of 3 to 6 are preferably used.
The silver ink of the present invention is prepared by mixing the raw materials described above, that is, two types of polyester resin and an aluminum pigment, and, in some cases, a wax and a polyisocyanate, and adding a concentration adjusting solvent to the mixture. Manufactured.
Furthermore, you may use the well-known adjuvant used for the printing ink as needed for the silver ink of this invention. For example, a plasticizer, a leveling agent, a surfactant, a dispersant, an antifoaming agent, etc. may be used.
With the above configuration, the silver ink of the present invention has improved adhesion to the packaging material base material and the UV offset ink, and the silver ink printing and the offset printing performed successively are used in normal offset printing. A silver ink that can withstand this even at a speed of 300 m / min was obtained.
The silver ink of the present invention is suitable for gravure printing and has high-speed printing suitability.
The thickness of the light-shielding printing layer using the silver ink of the present invention is preferably 1 to 10 μm. If the thickness is less than 1 μm, the light-shielding effect is insufficient, and if it exceeds 10 μm, not only is it practically excessive, but the cost is increased.
Furthermore, UV offset printing can be performed on the surface printed with the silver ink of the present invention, and the printing method is based on the usual method of UV offset printing. No special equipment is required for its use.
以下に実施例及び比較例を示して本発明を更に具体的に説明するが、これらに限定されるものではない。
なお、以下の記述で部又は％とあるのは、それぞれ重量部又は重量％を表す。
実施例１
ポリエステル樹脂バイロン５００（東洋紡績（株）製）５０部、ポリエステル樹脂バイロン１０３（東洋紡績（株）製）１０部、ポリエチレンワックスＨＹ−０４（三井化学（株）製）４部及びノンリーフィングタイプのアルミニウム顔料ＣＳ４３０ＹＣ（昭和アルミパウダー（株）製）２０部を混合し、さらに酢酸エチル１６部を添加して銀インキ１００部を得た。
実施例２及び３
実施例１と同様に、表１の組成に従って混合し、銀インキを得た。
比較例１~４
実施例１と同様に、表２の組成に従って混合して銀インキを得た。
なお、表１及び２に記載の原材料の各種物性は以下の方法により測定したものである。
１．アルミニウム顔料の平均粒子径
レーザ式粒度分布測定機（ＭＩＣＲＯＴＲＡＣ ９３２０−Ｘ１００ Ｈｏｎｅｙｗｅｌｌ製）による測定値である。
２．ガラス転移点（ポリエステル樹脂）
示差走査熱量測定 ＤＳＣにより、サンプル５ｍｇ、測定温度−６０~１２０℃、昇温速度２０℃／ｍｉｎの条件で測定された値である。
３．水酸基価（ポリエステル樹脂）
ＪＩＳ Ｋ １５５７−１に準じて測定した値である。
４．数平均分子量（ポリエステル樹脂）及び重量平均分子量（ポリエチレンワックス）
ゲル浸透クロマトグラフィー ＧＰＣにより、カラム温度３０℃、移動層溶媒テトラヒドロフラン、流速１．０ｍｌ／ｍｉｎの条件で、ポリスチレンを標準品として求めた値である。
比較試験例
実施例１~３及び比較例１~４の銀インキを用いて下記の〔ベタ印刷包装材の作成〕及び〔ＵＶオフセット印刷包装材の作成〕に従い夫々７種のベタ印刷包装材サンプル及びＵＶオフセット印刷包装材サンプルを作成し、耐摩擦性、耐水摩擦性、密着性（原反）、ＵＶインキ密着性、発色性、臭気の各項目について、比較試験を行いその評価を行った。
〔ベタ印刷包装材の作成〕
包装材基材として、市販のフィンランド国ストラエンソ社製のロール紙（幅５８７ｍｍ×長さ４０００ｍｍ×厚さ０．４３ｍｍのもので、上面に厚さ０．０１７ｍｍの外面熱可塑性樹脂層、下面に厚さ０．０２７ｍｍの内面熱可塑性樹脂層を設けたもの）を用意し、この包装材基材に夫々の構成の７種類のインキを用い、約３μｍの厚さにベタで毎分３００ｍの印刷速度でグラビア印刷をしてベタ印刷包装材を作成した。
〔ＵＶオフセット印刷包装材の作成〕
前記〔ベタ印刷包装材の作成〕で作成した７種のベタ印刷包装材の夫々に、ＵＶオフセットインキ（ＦＤカルトンＡＣＥ 墨、東洋インキ製造（株）製）を毎分３００ｍの印刷速度で印刷してＵＶオフセット印刷包装材を作成した。
〔比較試験〕
（１）、（２）耐摩擦性及び耐水摩擦性試験
前記〔ベタ印刷包装材の作成〕で得られた７種のベタ印刷包装材に対し、学振式堅牢度試験機（染色堅ろう度摩擦試験機ＦＲ−ＩＩ、スガ試験機（株）製）を用いて、ＪＩＳ−Ｐ８１３６に準じて荷重５００ｇで５０往復の摩擦試験を行った、摩擦紙の汚れた状態を汚染用グレースケールと比較して、汚れのないものを５として、５段階評価した。なお、耐水摩擦性の試験では、綿布に水を含ませたものを用いた。
（３）密着性試験（原反）
前記〔ベタ印刷包装材の作成〕で得られた７種のベタ印刷包装材に対し、セロハン粘着テープ（ニチバン（株）製 ＣＴ４０５ＡＰ−１８）を銀インキの印刷面に押し付けた後、そのセロハン粘着テープを剥がしたとき、テープ側にインキがほとんど取られていない場合を５、一部取られた場合を４、半分取られた場合３、半分以上取られた場合を２、ほとんど取られた場合を１として評価した。
（４）ＵＶインキ密着性試験
前記〔ＵＶオフセット印刷包装材の作成〕で得られた７種のＵＶオフセット印刷包装材に対し、セロハン粘着テープ（ニチバン（株）製 ＣＴ４０５ＡＰ−１８）をＵＶインキの印刷面に押し付けた後、そのセロハン粘着テープを剥がしたとき、テープ側にインキがほとんど取られていない場合を５、一部取られた場合を４、半分取られた場合３、半分以上取られた場合を２、ほとんど取られた場合を１として評価した。
（５）発色性（高速印刷時）試験
前記〔ベタ印刷包装材の作成〕で得られた７種のベタ印刷包装材に対し、（株）パーキンエルマージャパン製、ＬＡＭＢＤＡ９５０の分光光度計を用いて光透過率を測定し、可視光の透過率が最大となる波長において、その透過率が３％未満の場合を５、３~４％の場合を４、４~５％の場合を３、５~７％の場合を２、７％以上の場合を１と評価した。
（６）臭気
前記〔ベタ印刷包装材の作成〕で得られた７種のベタ印刷包装材に対し、パネラー３名がその臭いを嗅いで評価したが、実施例及び比較例の全てにおいてほとんど臭気が感じられなかった。
表３にその試験結果を纏めて記載したが、耐摩擦性、耐水摩擦性、密着性（原反）及び発色性（高速印刷時）はベタ印刷包装材を用い、ＵＶインキ密着性はＵＶオフセット印刷包装材を用いて評価したものである。
この試験結果を総括すると、本発明の実施例１~３の銀インキを用いたものと、比較例１~４の銀インキを用いたものとでは、耐摩擦性、耐水摩擦性及び密着性（原反）についてはほぼ同等で、臭気も殆ど感じられないが、本発明の実施例１~３の銀インキを用いたものは、比較例１~４の銀インキに比べ高速印刷時の発色性が優れている。即ち、銀インキを毎分３００ｍで高速印刷した場合でもカスレがなく、さらにその上にＵＶオフセット印刷したとき銀インキ印刷層と強く密着していることが解る。
試験例１
下記のサンプルを作成し、それぞれに印刷した層の側から光を照射して、その光の透過率の比較試験を行った。
〔光透過率用サンプルの作成〕
前記比較試験例で記載した包装材基材と同様のものを使用して、以下の試験用サンプルを作成した。
（サンプルＡ）前記包装材基材に実施例３記載の銀インキを用い、前記〔ベタ印刷包装材の作成〕と同様に毎分３００ｍの速度でベタ印刷をして、厚さ約３μｍの遮光性印刷層を設けたものである。
（サンプルＢ）前記包装材基材に、東京インキ（株）製ＬＲＣ−ＮＴ９１０墨を用い、毎分１５０ｍの速度で厚さ約３μｍに黒色ベタ印刷したものである。
（１）光透過率
サンプルＡ及びＢを、日本分光（株）製のＶ−６７０型紫外可視分光光度計を用いて、測定した。
光学系：シングルモノクロメータ
ツェルニターナマウント、ダブルビーム方式
光源：重水素ランプ（１９０~３５０ｎｍ）、ハロゲンランプ（３３０~２７００ｎｍ）
波長範囲：１９０~２７００ｎｍ
（スペクトルバンド幅 ０．５ｎｍ，紫外可視領域）
因みに、いわゆる可視光線は、４００~８００ｎｍの範囲とされているが、その範囲の前後を含めて測定した。
これによれば、高精度の測定ができ、測定波長範囲は１９０~２７００ｎｍ、スペクトルバンド幅０．５ｎｍである。
次に、その測定結果を示す。
（図１）（図２）
光の透過率が低いほど、サンプルの包装材としての遮光効果が高いことが示されている。
サンプルＡは、黒色印刷したもの（サンプルＢ）と遜色のない遮光効果が得られていることが解る。実用に十分耐え得る効果と評価できる。
試験例２
下記条件のサンプルを作り、これの官能検査を行い、その遮光効果の評価試験を行なった。
（サンプル１）前記実施例３記載の銀インキを用いて前記〔ベタ印刷包装材の作成〕に従い作成したベタ印刷包装材から、１リットル入りの紙パック容器（屋根型タイプ）を作成して、これに成分無調整牛乳を充填し密封した。
（サンプル２）市販されている標準的な１リットル入り紙パック容器（屋根型タイプ・遮光印刷のないもの）を作成して、これに成分無調整牛乳を充填し密封した。
何れのサンプルも、同時に同一条件で充填密封したものである。
（試験条件）
この牛乳入り密閉容器を店頭のショーウィンドウ型冷蔵庫内に１週間保管し、その風味に変化が生じたかどうかを官能試験による評価をした。
保存中の冷蔵庫内の庫内温度は４~８℃で、店内及びショーウィンドウの蛍光灯が連続して照射されている状態であった。
上記サンプルを室温に戻し、パネラー４名（味覚識別について特別なトレーニングを受けた専門家）により評価してもらった。
（評価方法）
試験方法はＳＤ法（ｓｅｍａｎｔｅｉｃ ｄｉｆｆｅｒｅｎｔｉａｌ ｍｅｔｈｏｄ）によった。ＳＤ法は、セマンティック・デファレンシャル法の略語であるが、サンプルの特性やイメージを種々の角度から描写できる。例えば、上品な−下品な、女性的−男性的、濃い−薄い、等の反対語を両極に置いた５~７段階の評価尺度を、１０~３０項目を用いる。パネルには、各特性又はイメージ項目ごとに、夫々該当する尺度上の位置（調査シート）に印を付けさせる。数値として得られた評価の平均値を求め、尺度上にプロットして各サンプルのプロフィールを描くことができる。解析には、主成分分析や因子分析等の多変量解析がしばしば使われる。
この試験では、以下（１）~（８）の官能評価の質問項目について、評点３~−３までの範囲で評価点を付け、評価を求めた。
（１）総合的な好ましさ
（２）口当たり良し悪し
（３）口中香り良し悪し
（４）喉ごし良し悪し
（５）甘み強さ
（６）フレッシュ感の有無
（７）濃厚感の有無
（８）後味良し悪し
前記評価点は、下記の尺度によるものである。
３ かなり好ましい
２ 好ましい
１ やや好ましい
０ どちらともいえない
−１ やや好ましくない
−２ 好ましくない
−３ かなり好ましくない
（考察）
この味覚評価の結果、サンプル１は、他のサンプルに比べて（１）総合的な好ましさにおいて顕著な有意差が見られた。また（２）口当たり良し悪し、（３）口中香り良し悪し、（４）喉ごし良し悪し、（６）フレッシュ感の有無、（８）後味良し悪し、の各項目においても、サンプル１は高い評価が認められた。
一方、（７）濃厚感の有無について、サンプル１の評価が低かったのは、「光劣化により牛乳成分が分離することによって、濃厚感が増して行く」と考えられるため、光劣化による成分分離を抑制する効果が確認されたものと考えられる。
サンプル１とサンプル２との比較では、遮光印刷層を設けていないものは、全体に評価が低い（特に（６）フレッシュ感の有無、（８）後味良し悪しについての評価が低い）。つまり、遮光性印刷層を設けたサンプルの方が、明らかに高い評価であることが認められる。
従って、遮光性印刷層を設けたサンプルの方が光照射による風味劣化が少ないことを確認した。
試験例３
金属探知機試験
前記実施例１~３記載の銀インキを用いて夫々前記〔ベタ印刷包装材の作成〕に従い作成したベタ印刷包装材から組み立てた紙パック容器を用いて、飲料等の生産ラインに設置されている金属探知機による金属反応の確認試験を行った。その結果、何れのものも金属反応を示さなかった。これにより、本発明の包装容器は、包装容器自体が金属探知機に反応しないから、本来、金属探知機に反応すべき金属異物の検知に支障を及ぼさないことが確認でき、生産ラインでの使用ができる。
使用した金属探知機は、アンリツ（株）製のＫ１１２１２７である。
検出精度は、鉄球１．５Φ、ＳＵＳ球３．０Φで行なった。 Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but is not limited thereto.
In the following description, “parts” or “%” means “parts by weight” or “% by weight”, respectively.
Example 1
50 parts of polyester resin Byron 500 (manufactured by Toyobo Co., Ltd.), 10 parts of polyester resin Byron 103 (manufactured by Toyobo Co., Ltd.), 4 parts of polyethylene wax HY-04 (manufactured by Mitsui Chemicals) and non-leafing type 20 parts of aluminum pigment CS430YC (manufactured by Showa Aluminum Powder Co., Ltd.) was mixed, and 16 parts of ethyl acetate was further added to obtain 100 parts of silver ink.
Examples 2 and 3
In the same manner as in Example 1, mixing was performed according to the composition shown in Table 1 to obtain a silver ink.
Comparative Examples 1-4
As in Example 1, silver ink was obtained by mixing according to the composition shown in Table 2.
The various physical properties of the raw materials listed in Tables 1 and 2 were measured by the following methods.
1. The average particle diameter of the aluminum pigment is a value measured by a laser particle size distribution analyzer (MICROTRAC 9320-X100 manufactured by Honeywell).
2. Glass transition point (polyester resin)
Differential scanning calorimetry This is a value measured by DSC under the conditions of 5 mg of sample, measurement temperature of −60 to 120 ° C., and heating rate of 20 ° C./min.
3. Hydroxyl value (polyester resin)
It is the value measured according to JIS K1557-1.
4). Number average molecular weight (polyester resin) and weight average molecular weight (polyethylene wax)
Gel permeation chromatography This is a value obtained by GPC using polystyrene as a standard product under conditions of a column temperature of 30 ° C., a moving bed solvent tetrahydrofuran, and a flow rate of 1.0 ml / min.
Comparative Test Example Seven types of solid printing packaging material samples according to [Preparation of solid printing packaging material] and [Preparation of UV offset printing packaging material] using the silver inks of Examples 1 to 3 and Comparative Examples 1 to 4, respectively. A UV offset printing packaging material sample was prepared, and a comparative test was performed and evaluated for each of the items of friction resistance, water friction resistance, adhesion (raw fabric), UV ink adhesion, color development, and odor.
[Creation of solid printing packaging materials]
As a packaging material base material, a commercially available roll paper made by Straenso, Finland (width 587 mm × length 4000 mm × thickness 0.43 mm, outer surface thermoplastic resin layer having a thickness of 0.017 mm on the upper surface and thickness on the lower surface Prepared with a 0.027 mm inner surface thermoplastic resin layer), and seven types of inks of each constitution were used for this packaging material base, and the printing speed was 300 m per minute with a solid thickness of about 3 μm. A solid print packaging material was created by gravure printing.
[Production of UV offset printing packaging materials]
UV offset ink (FD Carton ACE ink, manufactured by Toyo Ink Co., Ltd.) was printed at a printing speed of 300 m / min on each of the seven types of solid printing packaging materials prepared in [Preparation of solid printing packaging material]. A UV offset printing packaging material was prepared.
[Comparative test]
(1), (2) Friction resistance and water rub resistance test For the seven types of solid printing packaging materials obtained in [Preparation of solid printing packaging materials] Using a testing machine FR-II, manufactured by Suga Test Instruments Co., Ltd.), a 50-stroke friction test was performed with a load of 500 g in accordance with JIS-P8136. Then, 5 was evaluated as 5 with no contamination. In the water friction resistance test, a cotton cloth soaked with water was used.
(3) Adhesion test (raw fabric)
The cellophane adhesive tape (CT405AP-18 manufactured by Nichiban Co., Ltd.) was pressed against the silver ink printing surface against the seven types of solid print packaging materials obtained in [Preparation of solid printing packaging material], and then the cellophane adhesive When the tape is peeled, 5 when ink is hardly removed on the tape side, 4 when partially removed, 3 when half removed, 2 when almost half removed, 2 when almost removed Was evaluated as 1.
(4) UV ink adhesion test For the seven types of UV offset printing packaging materials obtained in [Preparation of UV offset printing packaging material], cellophane adhesive tape (CT405AP-18 manufactured by Nichiban Co., Ltd.) was used for UV ink. When the cellophane adhesive tape is peeled off after being pressed against the printing surface, 5 when ink is hardly removed on the tape side, 4 when partially removed, 3 when half removed, 3 or more removed. The case was evaluated as 2, and the case almost taken was evaluated as 1.
(5) Color development (at the time of high-speed printing) test Using the spectrophotometer of LAMBDA950, manufactured by PerkinElmer Japan Co., Ltd., for the seven types of solid printing packaging materials obtained in [Preparation of solid printing packaging materials]. The light transmittance is measured. At a wavelength where the transmittance of visible light is maximum, the transmittance is less than 3%, 5 is 3 to 4%, 4 is 4 to 5%, and 3 and 5 is the case. The case of ~ 7% was evaluated as 2, and the case of 7% or more was evaluated as 1.
(6) Odor Three panelists evaluated the smell of the seven solid print packaging materials obtained in [Preparation of solid print packaging material], but almost all of the examples and comparative examples were odorous. Was not felt.
The test results are summarized in Table 3, but solid printing packaging materials are used for friction resistance, water friction resistance, adhesion (raw fabric) and color development (during high-speed printing), and UV ink adhesion is UV offset. It is evaluated using a printing packaging material.
Summarizing the test results, friction resistance, water friction resistance, and adhesion (with the silver inks of Examples 1 to 3 of the present invention and the silver inks of Comparative Examples 1 to 4) ( The raw material) is almost the same and almost no odor is felt, but those using the silver inks of Examples 1 to 3 of the present invention have color development properties at high speed printing compared to the silver inks of Comparative Examples 1 to 4. Is excellent. That is, even when silver ink is printed at a high speed of 300 m / min, there is no blurring, and when UV offset printing is performed thereon, it can be seen that the silver ink is strongly adhered.
Test example 1
The following samples were prepared, light was irradiated from the printed layer side, and a comparative test of the light transmittance was performed.
[Preparation of light transmittance sample]
The following test samples were prepared using the same packaging material substrates described in the comparative test examples.
(Sample A) The silver ink described in Example 3 was used for the packaging material base material, and solid printing was performed at a speed of 300 m / min in the same manner as in [Preparation of solid printing packaging material]. In addition, a printable printing layer is provided.
(Sample B) LRC-NT910 black manufactured by Tokyo Ink Co., Ltd. was used for the packaging material base material, and black solid printing was performed to a thickness of about 3 μm at a speed of 150 m / min.
(1) Light transmittance Samples A and B were measured using a V-670 type ultraviolet-visible spectrophotometer manufactured by JASCO Corporation.
Optical system: Single monochromator Zernita mount, double beam system Light source: Deuterium lamp (190-350nm), Halogen lamp (330-2700nm)
Wavelength range: 190-2700nm
(Spectral bandwidth 0.5nm, UV-visible region)
Incidentally, the so-called visible light is in the range of 400 to 800 nm, and was measured including before and after that range.
According to this, high-accuracy measurement can be performed, the measurement wavelength range is 190 to 2700 nm, and the spectral bandwidth is 0.5 nm.
Next, the measurement result is shown.
(Fig. 1) (Fig. 2)
It is shown that the lower the light transmittance, the higher the light shielding effect as a sample packaging material.
It can be seen that Sample A has a light-shielding effect comparable to that printed on black (Sample B). It can be evaluated as an effect that can sufficiently withstand practical use.
Test example 2
The sample of the following conditions was made, the sensory test of this was performed, and the light shielding effect evaluation test was done.
(Sample 1) Using a silver ink as described in Example 3 above, a 1 liter paper pack container (roof type) is created from the solid printing packaging material prepared according to [Creation of solid printing packaging material] This was filled with non-adjusted milk and sealed.
(Sample 2) A commercially available standard 1 liter paper pack container (roof-type type, without light-shielding printing) was prepared, and this was filled with non-adjusted milk and sealed.
All samples were filled and sealed under the same conditions at the same time.
(Test conditions)
This milk-containing sealed container was stored in a store window refrigerator for one week, and whether or not the flavor had changed was evaluated by a sensory test.
The temperature inside the refrigerator during storage was 4 to 8 ° C., and the store and the fluorescent lamps in the show window were continuously irradiated.
The sample was returned to room temperature and evaluated by 4 panelists (experts with special training in taste discrimination).
(Evaluation methods)
The test method was based on the SD method (semantic differential method). The SD method is an abbreviation for Semantic Differential Method, but it can describe sample characteristics and images from various angles. For example, 10 to 30 items are used on a 5- to 7-level evaluation scale in which the opposite words such as refined-vulgar, feminine-masculine, dark-light, etc. are placed on both poles. The panel is marked for each characteristic or image item on the corresponding scale position (survey sheet). An average value of evaluations obtained as numerical values can be obtained and plotted on a scale to draw a profile of each sample. For analysis, multivariate analysis such as principal component analysis and factor analysis is often used.
In this test, the following (1) to (8) sensory evaluation question items were scored in the range of 3 to -3, and the evaluation was obtained.
(1) Overall preference (2) Good or bad taste (3) Good or bad smell in the mouth (4) Good or bad throat (5) Sweetness (6) Presence or absence of freshness (7) Presence or absence of richness (8) Good aftertaste The evaluation score is based on the following scale.
3 Pretty favorable 2Preferred 1 Somewhat preferred 0 Neither -1 Somewhat unfavorable-2 Unfavorable -3 Very unfavorable
(Discussion)
As a result of the taste evaluation,Sample 1 showed a significant difference in (1) overall preference compared to the other samples. In addition, sample 1 is high in each of the following items: (2) good and bad taste, (3) good and bad smell in mouth, (4) good and bad throat, (6) freshness and (8) good aftertaste Evaluation was accepted.
On the other hand, regarding (7) the presence or absence of richness, the evaluation ofSample 1 was low because it is considered that “the milky ingredient is separated due to light degradation, and the richness is increased”. It is considered that the effect of suppressing the above was confirmed.
In comparison betweenSample 1 and Sample 2, those not provided with the light-shielding print layer have a low overall evaluation (particularly (6) presence or absence of fresh feeling, (8) low evaluation of good or bad aftertaste). That is, it is recognized that the sample provided with the light-shielding print layer is clearly highly evaluated.
Therefore, it was confirmed that the sample provided with the light-shielding printing layer had less flavor deterioration due to light irradiation.
Test example 3
Metal detector test Using the silver ink described in Examples 1 to 3 to the production line for beverages, etc., using paper pack containers assembled from the solid printing packaging material prepared according to [Preparation of solid printing packaging material]. A metal reaction confirmation test was performed using the installed metal detector. As a result, none showed a metal reaction. As a result, the packaging container according to the present invention does not react to the metal detector, so that it can be confirmed that it does not hinder the detection of metal foreign objects that should react with the metal detector. Can do.
The metal detector used is K112127 manufactured by Anritsu Corporation.
The detection accuracy was performed with an iron ball of 1.5Φ and a SUS ball of 3.0Φ.
なお、以下の記述で部又は％とあるのは、それぞれ重量部又は重量％を表す。
実施例１
ポリエステル樹脂バイロン５００（東洋紡績（株）製）５０部、ポリエステル樹脂バイロン１０３（東洋紡績（株）製）１０部、ポリエチレンワックスＨＹ−０４（三井化学（株）製）４部及びノンリーフィングタイプのアルミニウム顔料ＣＳ４３０ＹＣ（昭和アルミパウダー（株）製）２０部を混合し、さらに酢酸エチル１６部を添加して銀インキ１００部を得た。
実施例２及び３
実施例１と同様に、表１の組成に従って混合し、銀インキを得た。
実施例１と同様に、表２の組成に従って混合して銀インキを得た。
１．アルミニウム顔料の平均粒子径
レーザ式粒度分布測定機（ＭＩＣＲＯＴＲＡＣ ９３２０−Ｘ１００ Ｈｏｎｅｙｗｅｌｌ製）による測定値である。
２．ガラス転移点（ポリエステル樹脂）
示差走査熱量測定 ＤＳＣにより、サンプル５ｍｇ、測定温度−６０~１２０℃、昇温速度２０℃／ｍｉｎの条件で測定された値である。
３．水酸基価（ポリエステル樹脂）
ＪＩＳ Ｋ １５５７−１に準じて測定した値である。
４．数平均分子量（ポリエステル樹脂）及び重量平均分子量（ポリエチレンワックス）
ゲル浸透クロマトグラフィー ＧＰＣにより、カラム温度３０℃、移動層溶媒テトラヒドロフラン、流速１．０ｍｌ／ｍｉｎの条件で、ポリスチレンを標準品として求めた値である。
比較試験例
実施例１~３及び比較例１~４の銀インキを用いて下記の〔ベタ印刷包装材の作成〕及び〔ＵＶオフセット印刷包装材の作成〕に従い夫々７種のベタ印刷包装材サンプル及びＵＶオフセット印刷包装材サンプルを作成し、耐摩擦性、耐水摩擦性、密着性（原反）、ＵＶインキ密着性、発色性、臭気の各項目について、比較試験を行いその評価を行った。
〔ベタ印刷包装材の作成〕
包装材基材として、市販のフィンランド国ストラエンソ社製のロール紙（幅５８７ｍｍ×長さ４０００ｍｍ×厚さ０．４３ｍｍのもので、上面に厚さ０．０１７ｍｍの外面熱可塑性樹脂層、下面に厚さ０．０２７ｍｍの内面熱可塑性樹脂層を設けたもの）を用意し、この包装材基材に夫々の構成の７種類のインキを用い、約３μｍの厚さにベタで毎分３００ｍの印刷速度でグラビア印刷をしてベタ印刷包装材を作成した。
〔ＵＶオフセット印刷包装材の作成〕
前記〔ベタ印刷包装材の作成〕で作成した７種のベタ印刷包装材の夫々に、ＵＶオフセットインキ（ＦＤカルトンＡＣＥ 墨、東洋インキ製造（株）製）を毎分３００ｍの印刷速度で印刷してＵＶオフセット印刷包装材を作成した。
〔比較試験〕
（１）、（２）耐摩擦性及び耐水摩擦性試験
前記〔ベタ印刷包装材の作成〕で得られた７種のベタ印刷包装材に対し、学振式堅牢度試験機（染色堅ろう度摩擦試験機ＦＲ−ＩＩ、スガ試験機（株）製）を用いて、ＪＩＳ−Ｐ８１３６に準じて荷重５００ｇで５０往復の摩擦試験を行った、摩擦紙の汚れた状態を汚染用グレースケールと比較して、汚れのないものを５として、５段階評価した。なお、耐水摩擦性の試験では、綿布に水を含ませたものを用いた。
（３）密着性試験（原反）
前記〔ベタ印刷包装材の作成〕で得られた７種のベタ印刷包装材に対し、セロハン粘着テープ（ニチバン（株）製 ＣＴ４０５ＡＰ−１８）を銀インキの印刷面に押し付けた後、そのセロハン粘着テープを剥がしたとき、テープ側にインキがほとんど取られていない場合を５、一部取られた場合を４、半分取られた場合３、半分以上取られた場合を２、ほとんど取られた場合を１として評価した。
（４）ＵＶインキ密着性試験
前記〔ＵＶオフセット印刷包装材の作成〕で得られた７種のＵＶオフセット印刷包装材に対し、セロハン粘着テープ（ニチバン（株）製 ＣＴ４０５ＡＰ−１８）をＵＶインキの印刷面に押し付けた後、そのセロハン粘着テープを剥がしたとき、テープ側にインキがほとんど取られていない場合を５、一部取られた場合を４、半分取られた場合３、半分以上取られた場合を２、ほとんど取られた場合を１として評価した。
（５）発色性（高速印刷時）試験
前記〔ベタ印刷包装材の作成〕で得られた７種のベタ印刷包装材に対し、（株）パーキンエルマージャパン製、ＬＡＭＢＤＡ９５０の分光光度計を用いて光透過率を測定し、可視光の透過率が最大となる波長において、その透過率が３％未満の場合を５、３~４％の場合を４、４~５％の場合を３、５~７％の場合を２、７％以上の場合を１と評価した。
（６）臭気
前記〔ベタ印刷包装材の作成〕で得られた７種のベタ印刷包装材に対し、パネラー３名がその臭いを嗅いで評価したが、実施例及び比較例の全てにおいてほとんど臭気が感じられなかった。
表３にその試験結果を纏めて記載したが、耐摩擦性、耐水摩擦性、密着性（原反）及び発色性（高速印刷時）はベタ印刷包装材を用い、ＵＶインキ密着性はＵＶオフセット印刷包装材を用いて評価したものである。
試験例１
下記のサンプルを作成し、それぞれに印刷した層の側から光を照射して、その光の透過率の比較試験を行った。
〔光透過率用サンプルの作成〕
前記比較試験例で記載した包装材基材と同様のものを使用して、以下の試験用サンプルを作成した。
（サンプルＡ）前記包装材基材に実施例３記載の銀インキを用い、前記〔ベタ印刷包装材の作成〕と同様に毎分３００ｍの速度でベタ印刷をして、厚さ約３μｍの遮光性印刷層を設けたものである。
（サンプルＢ）前記包装材基材に、東京インキ（株）製ＬＲＣ−ＮＴ９１０墨を用い、毎分１５０ｍの速度で厚さ約３μｍに黒色ベタ印刷したものである。
（１）光透過率
サンプルＡ及びＢを、日本分光（株）製のＶ−６７０型紫外可視分光光度計を用いて、測定した。
光学系：シングルモノクロメータ
ツェルニターナマウント、ダブルビーム方式
光源：重水素ランプ（１９０~３５０ｎｍ）、ハロゲンランプ（３３０~２７００ｎｍ）
波長範囲：１９０~２７００ｎｍ
（スペクトルバンド幅 ０．５ｎｍ，紫外可視領域）
因みに、いわゆる可視光線は、４００~８００ｎｍの範囲とされているが、その範囲の前後を含めて測定した。
これによれば、高精度の測定ができ、測定波長範囲は１９０~２７００ｎｍ、スペクトルバンド幅０．５ｎｍである。
次に、その測定結果を示す。
（図１）（図２）
光の透過率が低いほど、サンプルの包装材としての遮光効果が高いことが示されている。
サンプルＡは、黒色印刷したもの（サンプルＢ）と遜色のない遮光効果が得られていることが解る。実用に十分耐え得る効果と評価できる。
試験例２
下記条件のサンプルを作り、これの官能検査を行い、その遮光効果の評価試験を行なった。
（サンプル１）前記実施例３記載の銀インキを用いて前記〔ベタ印刷包装材の作成〕に従い作成したベタ印刷包装材から、１リットル入りの紙パック容器（屋根型タイプ）を作成して、これに成分無調整牛乳を充填し密封した。
（サンプル２）市販されている標準的な１リットル入り紙パック容器（屋根型タイプ・遮光印刷のないもの）を作成して、これに成分無調整牛乳を充填し密封した。
何れのサンプルも、同時に同一条件で充填密封したものである。
（試験条件）
この牛乳入り密閉容器を店頭のショーウィンドウ型冷蔵庫内に１週間保管し、その風味に変化が生じたかどうかを官能試験による評価をした。
保存中の冷蔵庫内の庫内温度は４~８℃で、店内及びショーウィンドウの蛍光灯が連続して照射されている状態であった。
上記サンプルを室温に戻し、パネラー４名（味覚識別について特別なトレーニングを受けた専門家）により評価してもらった。
（評価方法）
試験方法はＳＤ法（ｓｅｍａｎｔｅｉｃ ｄｉｆｆｅｒｅｎｔｉａｌ ｍｅｔｈｏｄ）によった。ＳＤ法は、セマンティック・デファレンシャル法の略語であるが、サンプルの特性やイメージを種々の角度から描写できる。例えば、上品な−下品な、女性的−男性的、濃い−薄い、等の反対語を両極に置いた５~７段階の評価尺度を、１０~３０項目を用いる。パネルには、各特性又はイメージ項目ごとに、夫々該当する尺度上の位置（調査シート）に印を付けさせる。数値として得られた評価の平均値を求め、尺度上にプロットして各サンプルのプロフィールを描くことができる。解析には、主成分分析や因子分析等の多変量解析がしばしば使われる。
この試験では、以下（１）~（８）の官能評価の質問項目について、評点３~−３までの範囲で評価点を付け、評価を求めた。
（１）総合的な好ましさ
（２）口当たり良し悪し
（３）口中香り良し悪し
（４）喉ごし良し悪し
（５）甘み強さ
（６）フレッシュ感の有無
（７）濃厚感の有無
（８）後味良し悪し
前記評価点は、下記の尺度によるものである。
３ かなり好ましい
２ 好ましい
１ やや好ましい
０ どちらともいえない
−１ やや好ましくない
−２ 好ましくない
−３ かなり好ましくない
この味覚評価の結果、サンプル１は、他のサンプルに比べて（１）総合的な好ましさにおいて顕著な有意差が見られた。また（２）口当たり良し悪し、（３）口中香り良し悪し、（４）喉ごし良し悪し、（６）フレッシュ感の有無、（８）後味良し悪し、の各項目においても、サンプル１は高い評価が認められた。
一方、（７）濃厚感の有無について、サンプル１の評価が低かったのは、「光劣化により牛乳成分が分離することによって、濃厚感が増して行く」と考えられるため、光劣化による成分分離を抑制する効果が確認されたものと考えられる。
サンプル１とサンプル２との比較では、遮光印刷層を設けていないものは、全体に評価が低い（特に（６）フレッシュ感の有無、（８）後味良し悪しについての評価が低い）。つまり、遮光性印刷層を設けたサンプルの方が、明らかに高い評価であることが認められる。
従って、遮光性印刷層を設けたサンプルの方が光照射による風味劣化が少ないことを確認した。
試験例３
金属探知機試験
前記実施例１~３記載の銀インキを用いて夫々前記〔ベタ印刷包装材の作成〕に従い作成したベタ印刷包装材から組み立てた紙パック容器を用いて、飲料等の生産ラインに設置されている金属探知機による金属反応の確認試験を行った。その結果、何れのものも金属反応を示さなかった。これにより、本発明の包装容器は、包装容器自体が金属探知機に反応しないから、本来、金属探知機に反応すべき金属異物の検知に支障を及ぼさないことが確認でき、生産ラインでの使用ができる。
使用した金属探知機は、アンリツ（株）製のＫ１１２１２７である。
検出精度は、鉄球１．５Φ、ＳＵＳ球３．０Φで行なった。 Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but is not limited thereto.
In the following description, “parts” or “%” means “parts by weight” or “% by weight”, respectively.
Example 1
50 parts of polyester resin Byron 500 (manufactured by Toyobo Co., Ltd.), 10 parts of polyester resin Byron 103 (manufactured by Toyobo Co., Ltd.), 4 parts of polyethylene wax HY-04 (manufactured by Mitsui Chemicals) and non-leafing type 20 parts of aluminum pigment CS430YC (manufactured by Showa Aluminum Powder Co., Ltd.) was mixed, and 16 parts of ethyl acetate was further added to obtain 100 parts of silver ink.
Examples 2 and 3
In the same manner as in Example 1, mixing was performed according to the composition shown in Table 1 to obtain a silver ink.
As in Example 1, silver ink was obtained by mixing according to the composition shown in Table 2.
1. The average particle diameter of the aluminum pigment is a value measured by a laser particle size distribution analyzer (MICROTRAC 9320-X100 manufactured by Honeywell).
2. Glass transition point (polyester resin)
Differential scanning calorimetry This is a value measured by DSC under the conditions of 5 mg of sample, measurement temperature of −60 to 120 ° C., and heating rate of 20 ° C./min.
3. Hydroxyl value (polyester resin)
It is the value measured according to JIS K1557-1.
4). Number average molecular weight (polyester resin) and weight average molecular weight (polyethylene wax)
Gel permeation chromatography This is a value obtained by GPC using polystyrene as a standard product under conditions of a column temperature of 30 ° C., a moving bed solvent tetrahydrofuran, and a flow rate of 1.0 ml / min.
Comparative Test Example Seven types of solid printing packaging material samples according to [Preparation of solid printing packaging material] and [Preparation of UV offset printing packaging material] using the silver inks of Examples 1 to 3 and Comparative Examples 1 to 4, respectively. A UV offset printing packaging material sample was prepared, and a comparative test was performed and evaluated for each of the items of friction resistance, water friction resistance, adhesion (raw fabric), UV ink adhesion, color development, and odor.
[Creation of solid printing packaging materials]
As a packaging material base material, a commercially available roll paper made by Straenso, Finland (width 587 mm × length 4000 mm × thickness 0.43 mm, outer surface thermoplastic resin layer having a thickness of 0.017 mm on the upper surface and thickness on the lower surface Prepared with a 0.027 mm inner surface thermoplastic resin layer), and seven types of inks of each constitution were used for this packaging material base, and the printing speed was 300 m per minute with a solid thickness of about 3 μm. A solid print packaging material was created by gravure printing.
[Production of UV offset printing packaging materials]
UV offset ink (FD Carton ACE ink, manufactured by Toyo Ink Co., Ltd.) was printed at a printing speed of 300 m / min on each of the seven types of solid printing packaging materials prepared in [Preparation of solid printing packaging material]. A UV offset printing packaging material was prepared.
[Comparative test]
(1), (2) Friction resistance and water rub resistance test For the seven types of solid printing packaging materials obtained in [Preparation of solid printing packaging materials] Using a testing machine FR-II, manufactured by Suga Test Instruments Co., Ltd.), a 50-stroke friction test was performed with a load of 500 g in accordance with JIS-P8136. Then, 5 was evaluated as 5 with no contamination. In the water friction resistance test, a cotton cloth soaked with water was used.
(3) Adhesion test (raw fabric)
The cellophane adhesive tape (CT405AP-18 manufactured by Nichiban Co., Ltd.) was pressed against the silver ink printing surface against the seven types of solid print packaging materials obtained in [Preparation of solid printing packaging material], and then the cellophane adhesive When the tape is peeled, 5 when ink is hardly removed on the tape side, 4 when partially removed, 3 when half removed, 2 when almost half removed, 2 when almost removed Was evaluated as 1.
(4) UV ink adhesion test For the seven types of UV offset printing packaging materials obtained in [Preparation of UV offset printing packaging material], cellophane adhesive tape (CT405AP-18 manufactured by Nichiban Co., Ltd.) was used for UV ink. When the cellophane adhesive tape is peeled off after being pressed against the printing surface, 5 when ink is hardly removed on the tape side, 4 when partially removed, 3 when half removed, 3 or more removed. The case was evaluated as 2, and the case almost taken was evaluated as 1.
(5) Color development (at the time of high-speed printing) test Using the spectrophotometer of LAMBDA950, manufactured by PerkinElmer Japan Co., Ltd., for the seven types of solid printing packaging materials obtained in [Preparation of solid printing packaging materials]. The light transmittance is measured. At a wavelength where the transmittance of visible light is maximum, the transmittance is less than 3%, 5 is 3 to 4%, 4 is 4 to 5%, and 3 and 5 is the case. The case of ~ 7% was evaluated as 2, and the case of 7% or more was evaluated as 1.
(6) Odor Three panelists evaluated the smell of the seven solid print packaging materials obtained in [Preparation of solid print packaging material], but almost all of the examples and comparative examples were odorous. Was not felt.
The test results are summarized in Table 3, but solid printing packaging materials are used for friction resistance, water friction resistance, adhesion (raw fabric) and color development (during high-speed printing), and UV ink adhesion is UV offset. It is evaluated using a printing packaging material.
Test example 1
The following samples were prepared, light was irradiated from the printed layer side, and a comparative test of the light transmittance was performed.
[Preparation of light transmittance sample]
The following test samples were prepared using the same packaging material substrates described in the comparative test examples.
(Sample A) The silver ink described in Example 3 was used for the packaging material base material, and solid printing was performed at a speed of 300 m / min in the same manner as in [Preparation of solid printing packaging material]. In addition, a printable printing layer is provided.
(Sample B) LRC-NT910 black manufactured by Tokyo Ink Co., Ltd. was used for the packaging material base material, and black solid printing was performed to a thickness of about 3 μm at a speed of 150 m / min.
(1) Light transmittance Samples A and B were measured using a V-670 type ultraviolet-visible spectrophotometer manufactured by JASCO Corporation.
Optical system: Single monochromator Zernita mount, double beam system Light source: Deuterium lamp (190-350nm), Halogen lamp (330-2700nm)
Wavelength range: 190-2700nm
(Spectral bandwidth 0.5nm, UV-visible region)
Incidentally, the so-called visible light is in the range of 400 to 800 nm, and was measured including before and after that range.
According to this, high-accuracy measurement can be performed, the measurement wavelength range is 190 to 2700 nm, and the spectral bandwidth is 0.5 nm.
Next, the measurement result is shown.
(Fig. 1) (Fig. 2)
It is shown that the lower the light transmittance, the higher the light shielding effect as a sample packaging material.
It can be seen that Sample A has a light-shielding effect comparable to that printed on black (Sample B). It can be evaluated as an effect that can sufficiently withstand practical use.
Test example 2
The sample of the following conditions was made, the sensory test of this was performed, and the light shielding effect evaluation test was done.
(Sample 1) Using a silver ink as described in Example 3 above, a 1 liter paper pack container (roof type) is created from the solid printing packaging material prepared according to [Creation of solid printing packaging material] This was filled with non-adjusted milk and sealed.
(Sample 2) A commercially available standard 1 liter paper pack container (roof-type type, without light-shielding printing) was prepared, and this was filled with non-adjusted milk and sealed.
All samples were filled and sealed under the same conditions at the same time.
(Test conditions)
This milk-containing sealed container was stored in a store window refrigerator for one week, and whether or not the flavor had changed was evaluated by a sensory test.
The temperature inside the refrigerator during storage was 4 to 8 ° C., and the store and the fluorescent lamps in the show window were continuously irradiated.
The sample was returned to room temperature and evaluated by 4 panelists (experts with special training in taste discrimination).
(Evaluation methods)
The test method was based on the SD method (semantic differential method). The SD method is an abbreviation for Semantic Differential Method, but it can describe sample characteristics and images from various angles. For example, 10 to 30 items are used on a 5- to 7-level evaluation scale in which the opposite words such as refined-vulgar, feminine-masculine, dark-light, etc. are placed on both poles. The panel is marked for each characteristic or image item on the corresponding scale position (survey sheet). An average value of evaluations obtained as numerical values can be obtained and plotted on a scale to draw a profile of each sample. For analysis, multivariate analysis such as principal component analysis and factor analysis is often used.
In this test, the following (1) to (8) sensory evaluation question items were scored in the range of 3 to -3, and the evaluation was obtained.
(1) Overall preference (2) Good or bad taste (3) Good or bad smell in the mouth (4) Good or bad throat (5) Sweetness (6) Presence or absence of freshness (7) Presence or absence of richness (8) Good aftertaste The evaluation score is based on the following scale.
3 Pretty favorable 2
As a result of the taste evaluation,
On the other hand, regarding (7) the presence or absence of richness, the evaluation of
In comparison between
Therefore, it was confirmed that the sample provided with the light-shielding printing layer had less flavor deterioration due to light irradiation.
Test example 3
Metal detector test Using the silver ink described in Examples 1 to 3 to the production line for beverages, etc., using paper pack containers assembled from the solid printing packaging material prepared according to [Preparation of solid printing packaging material]. A metal reaction confirmation test was performed using the installed metal detector. As a result, none showed a metal reaction. As a result, the packaging container according to the present invention does not react to the metal detector, so that it can be confirmed that it does not hinder the detection of metal foreign objects that should react with the metal detector. Can do.
The metal detector used is K112127 manufactured by Anritsu Corporation.
The detection accuracy was performed with an iron ball of 1.5Φ and a SUS ball of 3.0Φ.
本発明のインキを使用すると、遮光性を付与した紙パック容器が、低コストで生産ができる。
When the ink of the present invention is used, a paper pack container imparted with light shielding properties can be produced at low cost.
Claims (8)
- ポリエステル樹脂１００重量部に対して、アルミニウム顔料６０~１００重量部を含有している遮光性銀インキ組成物であって、
前記ポリエステル樹脂がガラス転移点−２０~１０℃、数平均分子量５０００~２５０００及び水酸基価５~２０のポリエステル樹脂と
ガラス転移点３０~１００℃、数平均分子量５０００~２５０００及び水酸基価５~２０のポリエステル樹脂とを含み、
その重量比率が１／１~１１／１であることを特徴とする遮光性インキ組成物。 A light-shielding silver ink composition containing 60 to 100 parts by weight of an aluminum pigment with respect to 100 parts by weight of a polyester resin,
The polyester resin has a glass transition point of −20 to 10 ° C., a number average molecular weight of 5000 to 25000 and a hydroxyl value of 5 to 20, and a glass transition point of 30 to 100 ° C., a number average molecular weight of 5000 to 25000 and a hydroxyl value of 5 to 20. Including polyester resin,
A light-shielding ink composition having a weight ratio of 1/1 to 11/1. - 前記遮光性銀インキ組成物に、ワックス２~１０重量部を添加したことを特徴とする請求項１記載の遮光性銀インキ組成物。 2. The light-shielding silver ink composition according to claim 1, wherein 2 to 10 parts by weight of wax is added to the light-shielding silver ink composition.
- 前記ワックスがポリエチレンワックスであることを特徴とする請求項１又は２記載の遮光性銀インキ組成物。 3. The light-shielding silver ink composition according to claim 1 or 2, wherein the wax is a polyethylene wax.
- 前記アルミニウム顔料が平均粒子径５~１５μｍのノンリーフィングタイプのアルミニウム顔料であることを特徴とする請求項１から３のいずれか１項に記載の遮光性銀インキ組成物。 The light-shielding silver ink composition according to any one of claims 1 to 3, wherein the aluminum pigment is a non-leafing type aluminum pigment having an average particle diameter of 5 to 15 µm.
- 前記遮光性銀インキ組成物に、更にポリイソシアネート１~１０重量部を添加したことを特徴とする請求項１から４のいずれか１項に記載の遮光性銀インキ組成物。 The light-shielding silver ink composition according to any one of claims 1 to 4, further comprising 1 to 10 parts by weight of polyisocyanate added to the light-shielding silver ink composition.
- 前記遮光性銀インキ組成物が、炭素数３~６のエステル系溶媒及び／又は炭素数３~６のケトン系溶媒を主成分とした溶媒中に溶解又は分散していることを特徴とする請求項１から５のいずれか１項に記載の遮光性銀インキ組成物。 The light-shielding silver ink composition is dissolved or dispersed in a solvent mainly composed of an ester solvent having 3 to 6 carbon atoms and / or a ketone solvent having 3 to 6 carbon atoms. Item 6. The light-shielding silver ink composition according to any one of items 1 to 5.
- 板紙基材の上面及び下面のそれぞれに合成樹脂の層を備えた積層包装材料のその表側になる面に請求項１から６のいずれか１項に記載の遮光性銀インキ組成物を用いて遮光性印刷層を設けると共に、前記遮光性印刷層の上にデザイン印刷層を設けたことを特徴とする遮光性包装材。 Light shielding using the light-shielding silver ink composition according to any one of claims 1 to 6 on the front surface of a laminated packaging material having a synthetic resin layer on each of an upper surface and a lower surface of a paperboard substrate A light-shielding packaging material comprising a light-sensitive printing layer and a design printing layer provided on the light-shielding printing layer.
- 請求項７記載の遮光性包装材から作成された包装容器。 A packaging container made from the light-shielding packaging material according to claim 7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/JP2009/070798 WO2011070685A1 (en) | 2009-12-08 | 2009-12-08 | Light-blocking silver ink composition and packaging containing using same |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/JP2009/070798 WO2011070685A1 (en) | 2009-12-08 | 2009-12-08 | Light-blocking silver ink composition and packaging containing using same |
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| Publication Number | Publication Date |
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| WO2011070685A1 true WO2011070685A1 (en) | 2011-06-16 |
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| Application Number | Title | Priority Date | Filing Date |
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| PCT/JP2009/070798 WO2011070685A1 (en) | 2009-12-08 | 2009-12-08 | Light-blocking silver ink composition and packaging containing using same |
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| Country | Link |
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| WO (1) | WO2011070685A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2018172138A (en) * | 2017-03-31 | 2018-11-08 | 凸版印刷株式会社 | Packaging material having light shielding property and concealing property |
| CN110028835A (en) * | 2019-05-07 | 2019-07-19 | 深圳市崯涛油墨科技有限公司 | A kind of silver lustre ink coating and preparation method thereof with stereoscopic effect on polycarbonate transparent material |
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| JPH0752328A (en) * | 1993-08-12 | 1995-02-28 | Toppan Printing Co Ltd | Laminated material for paper container |
| JP2002255158A (en) * | 2001-02-23 | 2002-09-11 | Nippon Paper Industries Co Ltd | Paper container for liquid |
| JP2003136652A (en) * | 2001-10-30 | 2003-05-14 | Toppan Printing Co Ltd | Shading laminated packaging material |
| JP2006063139A (en) * | 2004-08-25 | 2006-03-09 | Dainippon Ink & Chem Inc | Light-shielding ink, light-shielding film and heat-shrinkable label |
| JP2007230200A (en) * | 2006-03-02 | 2007-09-13 | Hokuetsu Package Kk | Light shielding packaging material, and light shielding packaging container using the same |
| JP2009051903A (en) * | 2007-08-24 | 2009-03-12 | Tokyo Printing Ink Mfg Co Ltd | Light-blocking ink |
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| JPH0752328A (en) * | 1993-08-12 | 1995-02-28 | Toppan Printing Co Ltd | Laminated material for paper container |
| JP2002255158A (en) * | 2001-02-23 | 2002-09-11 | Nippon Paper Industries Co Ltd | Paper container for liquid |
| JP2003136652A (en) * | 2001-10-30 | 2003-05-14 | Toppan Printing Co Ltd | Shading laminated packaging material |
| JP2006063139A (en) * | 2004-08-25 | 2006-03-09 | Dainippon Ink & Chem Inc | Light-shielding ink, light-shielding film and heat-shrinkable label |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP2018172138A (en) * | 2017-03-31 | 2018-11-08 | 凸版印刷株式会社 | Packaging material having light shielding property and concealing property |
| CN110028835A (en) * | 2019-05-07 | 2019-07-19 | 深圳市崯涛油墨科技有限公司 | A kind of silver lustre ink coating and preparation method thereof with stereoscopic effect on polycarbonate transparent material |
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