JP2016108440A - Antistatic gravure white ink for reverse printing and substrate plastic film for dry laminate reverse-printed with use of the white ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gravure white ink for reverse printing that has antistatic property imparted economically inexpensively by adding an extender pigment and to provide a substrate film for laminate.SOLUTION: An ethyl acetate solution using as a main agent an inorganic salt of calcium nitrate and as an auxiliary agent lauryl (dodecanyl)dimethyl ethyl ammonium ethyl sulfate and propylene carbonate is added to a gravure white ink for reverse printing and printing is carried out by using the gravure white ink to produce a useful and antistatic substrate plastic film for dry laminate.SELECTED DRAWING: None

Description

  The present invention relates to a gravure white ink for back printing imparted with an antistatic property for a plastic film, and a base plastic film for dry lamination printed using this white ink.

  Generally, a plastic laminated film used for food packaging or the like is charged with static electricity when it is rubbed or peeled off, and this static electricity causes trouble especially on an automatic filling machine such as confectionery and food.

  In order to avoid this charging phenomenon, antistatic measures are taken such as kneading or applying an antistatic agent to the plastic film, or adding it to an adhesive used for lamination. However, the kneading and coating method leads to an increase in cost due to the addition of processing steps, and the addition method to the adhesive may weaken the cohesive force of the adhesive and impair the physical properties of the laminated film.

  For this reason, a method for applying an antistatic agent to gravure ink is introduced in Japanese Patent Application Laid-Open No. 2000-290082.

  This known example can reduce printing defects due to static electricity generated during gravure ink printing, and further obtain a gravure ink that does not deteriorate the fluidity of the ink and the adhesion to the printing film. The content of the ink composition is 0.03 to 0.09 part of an antistatic agent containing bis (hydroxyethyl) methyl and cocoalkylbis (hydroxyethyl) methyl chloride as components.

  In addition, JP 2011-162663 A can reduce printing defects due to static electricity generated at the time of gravure ink printing, and further, stability of ink diameter, adhesion to a printing film, and when printed matter is wound. Gravure ink printing that does not reduce the procking property, boilability of the laminate, etc. Four alkyl groups R1, R2, R3, R4 bonded to N with polyurethane resin as the main binder are each R1 is carbon number The quaternary ammonium salt contains 8 to 22 alkyl groups, R2 and R3 are methyl groups, and R4 is an alkyl group having 1 to 18 carbon atoms or a benzyl group.

  However, in the case of the above-mentioned known examples, none of the white inks are used for back printing, so it is necessary to apply antistatic processing to each color ink, and it takes cost and labor to manufacture the ink, and because it is an organic solvent type However, there is a problem that the working environment and the natural environment are deteriorated.

  The present invention provides antistatic performance to a gravure white ink for back printing applied to a plastic laminated film, and provides a gravure white ink for back printing that leads to a reduction in ink cost, which is a feature of extender pigments. Objective.

  In order to solve the above problems, the invention described in claim 1 is characterized in that in the gravure white ink for back printing, an extender pigment comprising an inorganic salt solution imparted with antistatic properties is added and mixed. It is.

  Next, the invention according to claim 2 is the gravure white ink for back printing according to claim 1, wherein the extender pigment is a mixed solution in which ethyl acetate and tartarptanol are mixed at a ratio of 10: 1. It consists of a dissolved colorless and transparent inorganic salt solution having a solid content concentration of 50%.

  Next, the invention according to claim 3 is the gravure white ink for back printing according to claim 1 or 2, wherein the extender pigment of the inorganic salt solution is added and mixed in a solid content ratio of 6 to 10%. It is characterized by.

  Next, the invention according to claim 4 is the gravure white ink for back printing according to any one of claims 1 to 3, wherein the solid main component of the inorganic salt solution of the extender pigment is calcium nitrate. It is a hydrate and is characterized by alkyl dimethyl ethyl ammonium ammonium ethosulphate and propylene carbonate as auxiliary agents, the weight ratio of which is set to 70:15:15.

  Next, the invention according to claim 5 is that the base plastic film for dry lamination is back printed using the gravure white ink for back printing according to any one of claims 1 to 4. It is a feature.

  According to the present invention, the gravure white ink used for the back-printing of a plastic film imparts excellent antistatic properties without impairing its adhesive properties (stagnation, scratching, tape peeling), water resistance and heat resistance. It is a technology that can be widely used as a general packaging bag or a boiled retort bag by being used for back printing of a plastic film and being laminated with another film.

  Further, in the antistatic gravure white ink according to the present invention, by using the mixed solution of extender pigment according to any one of claims 1 to 4 as an antistatic agent, the adhesion of the printed white ink used on the back printing surface is achieved. It is possible to obtain a dry laminate base film having a high degree of durability and a little deterioration with time.

  In addition, the auxiliary agent according to claim 4 used in the present invention is a non-toluene type, so that it has excellent photographic printability, in particular, excellent appearance of gradation effect. Can be obtained.

  Moreover, since it is a non-toluene type, there is no toxicity and it is possible to obtain a gravure white ink and a dry laminate base film that are friendly to the working environment and the natural environment.

  When packaging dried food in laminated film bags, static electricity is generated when the bags are taken out one by one, and this frequently charges the film, causing troubles to take two bags. In addition, when filling the inside of the bag with dried food, the crushed material is diffused and adhered due to static electricity, which causes a drop in food value. As this preventive measure, an antistatic film by the above-described method is selected, but the cost increases.

  When packages such as candy and chocolate are individually packaged by a high-speed automatic filling and packaging machine, strong peeling electrification occurs at the feeding portion of the roll-shaped laminate film. Furthermore, frictional charging occurs between the guide roll and the guide plate subjected to traveling control, and traveling stability is impaired by the attractive force and the repulsive force. This phenomenon tends to occur especially in winter when the humidity is low.

  General-purpose gravure white ink is widely used in snacks. Its function is to make the photographic print pattern of the contents important to appeal the product stand out from the back by whitening, or to delay the oxidation of fats and oils by blocking the ultraviolet rays of the fluorescent lamp at the time of display Is applied. White ink accounts for about 50% or more of the total amount of general-purpose gravure backprinting white ink used.

  It has been found that if the antistatic agent of the present invention (the above-mentioned extender pigment) is added to this white ink, the antistatic performance can be easily imparted and the cost is not increased.

First, the constitution of the main component inorganic salt and auxiliary agent according to claim 4 will be described below.

  In order to confirm the antistatic performance, the above-described inorganic salt, calcium nitrate tetrahydrate (A), auxiliary agents alkyldimethyl, ethyl, ammonium, ethyl sulfate (B) and propylene carbonate (C), which are the main constituents of the extender of the present invention, are used. It was added to a solvent-type gravure white ink for non-toluene type film manufactured by Toyo Ink Co., Ltd. and adjusted as shown in Table 1.

The mixing ratio of the antistatic agent of calcium nitrate tetrahydrate (a) + auxiliary (Chemical Formula 2 ... b) + auxiliary (Chemical Formula 3 ... c) is 70:15:15.
[Formulation 1] A (1 kg) + a (0 g) + b (0 g) + c (0 g) + ethyl acetate diluted solution 300 g
[Formulation 2] A (1 kg) + a (42 g) + b (9 g) + c (9 g) + diluted solution 300 g
[Formulation 3] A (1 kg) + a (70 g) + b (15 g) + c (15 g) Diluent 300 g

  The engraving gravure and all solids (54 lines) were set in the second color unit of an 8-color gravure ink printer manufactured by Fuji Kikai Kogyo Co., Ltd., and each of the above formulations was printed on biaxially stretched PET12μ (Diafoil H500). The dryer used only the first to third color units, the drying temperature was set to 70 ° C., and printing was performed at a printing speed of 150 m / min.

(Prototype 1) PET 12 μ + [Formulation 1 / Standard white ink]
(Prototype 2) PET 12 μ + [Formulation 2 / Formulation 1 + Antistatic Agent of the Present Invention]
(Prototype 3) PET 12 μ + [Formulation 3 / Formulation 1 + Antistatic agent of the present invention

  Each prototype was printed with each formulation. In simple adhesive strength evaluation of biaxially stretched PET of white ink, as shown in Table 2, no change was observed in the adhesive strength regardless of whether or not the antistatic agent of the present invention was added.

  Tape adhesion / A commercially available cellophane adhesive tape was affixed to the ink surface and then forcedly peeled to evaluate the peeled state of the ink. Scratching / Scratching the ink surface with a needle made of polyacetal resin to evaluate the peeled state. The stagnation / ink surface is rubbed together and the peeled state is evaluated. The results are shown in Table 3.

[Formulation 1] A (1 kg) + a (0 g) + b (0 g) + ethyl acetate diluted solution 300 g
[Formulation 2] A (1 kg) + a (42 g) + b (18 g) + ethyl acetate diluted solution 300 g
[Formulation 3] A (1 kg) + a (70 g) + b (30 g) + ethyl acetate diluted solution 300 g

  The engraving gravure and all solids (54 lines) were set in the second color unit of an 8-color gravure ink printer manufactured by Fuji Kikai Kogyo Co., Ltd., and each of the above formulations was printed on biaxially stretched PET12μ (Diafoil H500). The dryer used only the first to third color units, the drying temperature was set to 70 ° C., and printing was performed at a printing speed of 150 m / min.

(Prototype 1) PET 12 μ + [formulation 1 / standard white ink]
(Prototype 2) PET 12 μ + [Formulation 2 / Formulation 1 + Antistatic agent of the present invention]
(Prototype 3) PET 12 μ + [Formulation 3 / Formulation 1 + Antistatic agent of the present invention]

  Each trial was printed with each formulation. In simple adhesive strength evaluation of biaxially stretched PET of white ink, as shown in Table 4, no change was observed in the adhesive strength regardless of whether or not the antistatic agent of the present invention was added.

  Tape adhesion / A commercially available cellophane adhesive tape was applied to the ink surface and then forcedly peeled to evaluate the ink peeling state. The scratched / ink surface was evaluated with a needle made of polyacetal resin to evaluate the peeled state of the scratched ink. The stagnation / ink surface is rubbed together and the peeled state is evaluated. Table 5 shows the measurement results of the surface specific resistance value and the frictional voltage of (Prototype 1).

For measurement of the surface resistivity, Electro-systems. inc. Made Wide
A Range Resistance Indicator Model 860 was used.

  A static electricity measuring device SV-511 manufactured by Nihon Sttech Co., Ltd. was used for the measurement of the frictional voltage value.

  The term “immediately after rubbing” refers to a measurement value immediately after rubbing 10 times in a reciprocating manner by placing the printed surface against a woolen fabric placed on the knee. 10 seconds later means a measured value 10 seconds after immediately after friction.

  Each prototype film printed on PET 12μ with each formulation was dry-laminated with 50μ general-purpose CPP (KT) manufactured by Sun Tox Co., Ltd. to obtain [Prototype 2]. The adhesive used was an aromatic ether-based main ingredient Takelac A977 / curing agent Takenate A92 (solid content 30%) manufactured by Mitsui Chemicals, Inc., and was bonded with a dry laminator (FL2 / series) manufactured by Fuji Machine Industry Co., Ltd. The amount of adhesive applied was 2.6 g / square meter, and physical properties after aging at 40 ° C. for 72 hours were evaluated.

(Prototype 4) PET 12 μ + {Formulation 1} + Adhesive + CPP 50 μ
(Prototype 5) PET 12 μ + [Composition 2] + Adhesive + CPP 50 μ
(Prototype 6) PET 12 μ + [Formulation 3] + Adhesive + CPP 50 μ

  Table 6 shows the measurement results of the frictional voltage value of each prototype.

  For the measurement of the frictional voltage value, a static measuring device SV-511 manufactured by Nihon Statech Co., Ltd. was used.

  Table 7 shows the laminate strength measurement results of each prototype.

  A non-toluene urethane white ink base manufactured by Sakata Inx Co., Ltd. was selected as the gravure ink for general-purpose film, and the antistatic agent and auxiliary agent of the present invention were added. The above configuration is shown in Table 8.

  Bell Color R White 115 / Ink Base) is composed of resin (30%), pigment (30%), auxiliary agent (5%), and organic solvent (35%), and the solid content concentration is 65%. This ink base (10 kg) was mixed with a special solvent (3 kg). The viscosity was measured at 3 to prepare a white ink for printing (solid concentration 50%) for 17 seconds [C].

[Formulation 5] C (10 kg) + a (-0 g) + b (-0 g)
[Formulation 6] C (10 kg) + a (350 g) + b (150 g)

  The total proportion of the antistatic agent and auxiliary agent was adjusted to 10% with respect to the solid content of the ink. Using the inks of [Formulation 5] and [Formulation 6], printing was performed by Nakajima Seiki Co., Ltd. 5-color gravure printing machine (GT-5 type). The drying speed was 55 ° C. from the first color unit to the fourth color unit. The fifth color unit was set at 70 ° C. and the speed was 80 m / min.

  The films used were the brands shown in Table 6 and the corona-treated surface was the printing surface.

  After adhering the tape adhesive / commercial cellophane adhesive tape to the ink surface, it was forcibly peeled and the peeled state of the ink was evaluated. Scratching / Scratching the ink surface with a needle made of polyacetal resin to evaluate the ink peeling state. The stagnation / peeling state is evaluated by rubbing the stagnation / ink surfaces.

  Each ink-printed surface was smooth, and the measurement results of the surface specific resistance value and the frictional voltage value were obtained as shown in Table 10.

  The surface specific resistance value was measured using a Wide Range Resistance Indicator Model 860 manufactured by Electro-tech systems.

  The printed film was laminated by dry lamination with a sealant film. Table 11 was selected for the brand and thickness of the sealant film.

  Adhesive is ether-based polyurethane (Takelac (R) A / Takenate (R) A) manufactured by Mitsui Chemicals, Inc. and dry laminator is manufactured by Orient Kogyo Co., Ltd. (J-133 type). did. The composition of the adhesive is shown in Table 12.

  The amount of adhesive applied was 2.0 g / square meter. The laminated structure is as shown in Table 13.

  Table 14 shows the measurement results of the frictional voltage value of each laminated material.

  For measurement of the frictional voltage value, a static electricity measuring device SV-511 manufactured by Nihon Statech Co., Ltd. was used.

  Immediately after rubbing is a measured value immediately after rubbing the printed surface against the wool fabric placed on the knee 10 times.

  “After 10 seconds” means a measurement value 10 seconds after immediately after the test.

  Table 15 shows the measurement results of the laminate strength (peel strength) of each laminate.

  A4 size bags were made with each laminated laminate film. Table 16 shows the heat seal strength of MD and TD.

  Table 17 shows the results of visually inspecting the properties of the bags after cooling and drying, filling and sealing the bags made of each laminated laminate film with water, sealing and boiling in 85 ° C. hot water for 1 hour.

  After boiling, no change in the properties of the bag with the white ink of the present invention was observed.

  Table 18 shows the measurement results of the laminate strength (isolation strength) of each laminated material bag after boiling.

  Table 19 shows the MD and TD heat seal strength of each laminated material bag after boiling.

The ratio of antistatic agent (c) and auxiliary agent (d) of the present invention described above in Tables 20 and 21 are non-toluene solvent-type gravure white inks manufactured by Toyo Ink Co., Ltd. for confirming antistatic agent performance. To adjust the following.

  The white ink adjusted according to the composition breakdown in the above table was printed on a corona discharge-treated surface of biaxially stretched PET 12 μm with a gravure small proofing machine.

  Table 22 shows the simple adhesive strength evaluation of the white ink on the corona discharge treated surface of biaxially stretched PET 12μ printed with the above formulation.

  Adhesion of tape / A commercially available cellophane adhesive tape is applied to the ink surface, and then it is forcibly peeled to evaluate the peeled state of the ink. Scratching / Scratching the ink surface with a needle made of polyacetal resin to evaluate the ink peeling state. The stagnation / peeling state is evaluated by rubbing the stagnation / ink surfaces.

  Table 23 shows the measurement results of electrical resistivity and frictional voltage value of the printing surface of the white ink having the above composition.

  The white ink adjusted according to the composition breakdown in the above table was printed on a corona discharge-treated surface of biaxially stretched PET 12 μm with a gravure small proofing machine.

  Table 24 shows a simple adhesive strength evaluation with white ink on the corona discharge-treated surface of biaxially stretched PET 12μ printed with the above formulation.

  Table 25 shows the measurement results of the specific resistance value and the frictional voltage value of the printing surface of the white ink having the above composition.

Claims (5)

  A gravure white ink for back printing comprising an additive pigment composed of an inorganic salt solution imparted with antistatic properties. 2. The extender pigment is composed of a colorless and transparent 50% solid content inorganic salt solution dissolved in a mixed solution in which ethyl acetate and tert-butanol are mixed at a ratio of 10: 1. Gravure white ink for back printing as described in 1.   The gravure white ink for back printing according to claim 1 or 2, wherein the extender pigment of the inorganic salt solution is added and mixed in a solid content ratio of 6 to 10%.   The solid main component of the inorganic salt solution of the extender pigment is calcium nitrate tetrahydrate, and the auxiliary components are alkyl, dimethyl, ethyl, ammonium, ethosulfate and propylene carbonate, and the weight component ratio is 70:15: The gravure white ink for back printing according to any one of claims 1 to 3, wherein the white ink is set to 15.   A base plastic film for dry lamination which is back-printed using the gravure white ink for back printing according to any one of claims 1 to 4.